Patent Publication Number: US-2022220998-A1

Title: Rivetless fastener and installation tool

Description:
RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 16/138,253, filed Sep. 21, 2018, which claims priority to and the benefit of U.S. Provisional Patent Application No. 62/562,003, filed Sep. 22, 2017, U.S. Provisional Patent Application No. 62/643,636, filed Mar. 15, 2018, and U.S. Provisional Patent Application No. 62/673,502, filed May 18, 2018, each of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD 
     A rivetless fastener and installation tools are disclosed, and more particularly, a rivetless fastener having a thin-walled bushing and an installation tool configured for measuring forces when installing a fastener in a structure. 
     BACKGROUND 
     Existing nut plates and similar fasteners suffer from several disadvantages. For example, some nut plates attach only to the surface of a structure via adhesive only, resulting in relatively weak attachment and a corresponding tendency to come loose and fall of the structure. Further, any coldworking of a bolt hole in the structure must be done separately from the installation of such nut plates, thereby increasing labor and cost. Other nut plates include a barrel that extends and is expanded within a bolt hole in the structure; however, the thick barrel walls require increased hole diameters, which can reduce edge distance of the hole and reduce lifespan of the structure. Further nut plates have multi-piece constructions including a sleeve that does not play a role in anchoring these nut plates to the hole in the structure, and these nut plates suffer from low torque out thresholds and other disadvantages. Further, the growing use of composite substructure in airframes is creating the need for a better solution for fastening systems, particularly for blind portions of major assemblies. The use of the traditional riveted nut plate retainer is problematic due to the cost of drilling holes in composites, particularly the small holes required for nut plate rivets. Currently other options are limited and include surface bonded retainers, which have a well-deserved reputation for falling off, and expanded retainers that depend on friction for retention while limited to very low expansion levels. Thus, there is a need for improved fasteners. 
     SUMMARY 
     The present disclosure is directed to a fastener for retaining a bolt in a hole in a structure. The fastener, in various embodiments, may comprise a retainer having a bottom surface for positioning against a surface of the structure surrounding the hole, and a bushing integrally formed with and extending from the bottom surface of the retainer, the bushing being dimensioned for insertion into the hole in the structure and having a wall thickness ranging from about 0.005 inches to about 0.030 inches. The bushing may be configured to be expanded within the hole, thereby securely coupling the expanded bushing within the hole of the structure and anchoring the retainer to the surface of the structure surrounding the hole. 
     The retainer, in various embodiments, may include a nut, or a coupler for receiving a nut, for securing the bolt. The fastener, in various embodiments, may be machined from a single piece of metallic material. 
     The bushing, in various embodiments, may have a substantially hollow cylindrical shape. The wall thickness of the bushing, in various embodiments, may minimize a diameter of the hole required for accommodating the bushing and the bolt inside of the hole. The bushing, in various embodiments, may be configured to be expanded by about 3.5% within the hole. Expansion of the bushing, in some embodiments, may securely couple the bushing with the hole of the structure via at least friction fit. 
     The fastener, in various embodiments, may further comprise an adhesive material positioned on at least one of the first side of the retainer and an outer surface of the bushing. In some embodiments, the adhesive material may be positioned on at least the outer surface of the bushing, and expansion of the bushing enhances a bond between the adhesive material and the hole. The enhanced bond between the adhesive material and the hole may act to securely couple the expanded bushing within the hole of the structure. In an embodiment, the adhesive may be pressure activated. 
     In another aspect, the present disclosure is directed to a tool for installing a fastener to a structure. The tool, in various embodiments, may comprise a mandrel having a tapered shape, the mandrel configured for insertion within a fastener situated within a hole of the structure, a drive mechanism configured to retract the mandrel through the fastener and thereby expand the fastener within the hole of the structure, and a force sensor configured for measuring a force applied by the drive mechanism to retract the mandrel through the fastener. 
     The drive mechanism, in various embodiments, may include a lead screw coupled with a threaded sleeve. Rotating the lead screw may cause the threaded sleeve to move axially to retract and extend the mandrel. In an embodiment, a head of the lead screw may be configured to couple with at least one of an electric drill and an impact driver. In another embodiment, the tool may include an integrated drive device for driving the drive mechanism. 
     The tool, in various embodiments, may further comprise a free-floating component situated adjacent to the force sensor and partially extending from a distal end of a housing of the tool. The free-floating component may be configured to transmit, to the force sensor, a pressure generated between the free-floating component and the structure when the mandrel is retracted to expand the fastener. The tool, in various embodiment, may further comprise a first pressure plate and a second pressure plate situated on opposing sides of the force sensor, the first pressure plate and the second pressure plate acting to evenly distribute and direct forces applied by the free-floating component to act perpendicular to the force sensor. 
     The tool, in various embodiments, may further comprise a processor configured to determine at least one of a maximum force applied during installation of the fastener and a total force applied throughout the installation of the fastener. The processor, in an embodiment, may be configured to store, or transmit for remote storage, at least one of the maximum force and the total force. The processor, in an embodiment, may be further configured to compare at least one of the measured maximum force and the measured total force to a predetermined range of corresponding forces, the predetermined range defining a range of forces indicative of a successful installation, and automatically provide a notification to a user of the tool indicating whether the measured force is within the predetermined range. 
     The tool, in various embodiments, may further comprise a radio frequency identification (RFID) reader positioned near a distal end of the tool. The RFID reader may be configured to automatically scan an RFID tag located on or in the fastener, and the processor may be configured to associate at least one of the maximum force and the total force with an identification of the RFID tag. 
     In yet another aspect, the present disclosure is directed to a tool for measuring a force associated with installation of a fastener in a structure. The tool, in various embodiments, may comprise a housing adapter shaped and dimensioned for coupling to a nosepiece of a mandrel pulling tool, a mandrel having a tapered shape, the mandrel having a proximal end configured for coupling to the mandrel pulling tool and a distal portion configured for insertion within a fastener situated within a hole of the structure, and a force sensor configured for automatically measuring a force applied by the drive mechanism to retract the mandrel through the fastener during installation. 
     The tool, in various embodiments, may further comprise a free-floating component situated adjacent to the force sensor and partially extending from a distal end of the housing adapter. The free-floating component may be configured to transmit, to the force sensor, a pressure generated between the free-floating component and the structure when the mandrel is retracted to expand the fastener. The tool, in various embodiments, may further comprise a first pressure plate and a second pressure plate situated on opposing sides of the force sensor, the first pressure plate and second pressure plate acting to evenly distribute and direct forces applied by the free-floating component to act perpendicular to the force sensor. 
     The tool, in various embodiments, may further comprise a processor configured to determine at least one of a maximum force applied during installation of the fastener and a total force applied throughout the installation of the fastener. The processor may be configured to store, or transmit for remote storage, at least one of the maximum force and the total force. The processor, in an embodiment, may be further configured to compare at least one of the measured maximum force and the measured total force to a predetermined range of corresponding forces, the predetermined range defining a range of forces indicative of a successful installation, and automatically provide a notification to a user of the tool indicating whether the measured force is within the predetermined range. 
     The tool, in various embodiments, may further comprise a radio frequency identification (RFID) reader positioned near a distal end of the tool. The RFID reader may be configured to automatically scan an RFID tag located on or in the fastener, and the processor may be configured to associate at least one of the maximum force and the total force with an identification of the RFID tag. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of a representative embodiment of fastener  100  of the present disclosure; 
         FIG. 2A ,  FIG. 2B ,  FIG. 2C , and  FIG. 2D  illustrate front, side, top, and bottom views of fastener  100 ; 
         FIG. 2E  depicts coupler  114  including a groove  115  for receiving a spring clip  115   a  configured to secure nut  116  on fastener  100 ; 
         FIG. 3A ,  FIG. 3B , and  FIG. 3C  illustrate top, side, and cross-sectional views of a representative embodiment of fastener  100  as installed in hole  12  of structure  10 ; 
         FIG. 4A  and  FIG. 4B , illustrate another approach for installing fastener  100  on structure  10  in accordance with a representative embodiment of the present disclosure; 
         FIG. 4C  illustrates in an embodiment, fastener  100  may include one or more holes  118  extending through retainer  110  for enhancing the adhesive bond between retainer  110  and the surface of structure  10  surrounding hole; 
         FIG. 5  is a chart comparing aspects of fastener  100  of the present disclosure with those of existing nut plates; 
         FIG. 6A  and  FIG. 6B  depict the representative embodiments of fastener  100  and a thick-walled nut plate; 
         FIG. 7A ,  FIG. 7B , and  FIG. 7C  illustrate the variations in required hole diameters and resulting edge distances of the thin-walled fastener  100  and a representative thick-walled nut plate; 
         FIG. 8  depicts constant amplitude fatigue testing as performed on coupons using a dogbone geometry; 
         FIG. 9A  graphically displays results of several constant amplitude Fatigue Life Tests performed by University of Dayton Research Institute in graphical form, with a constant stress level of 35 KSI; 
         FIG. 9B  graphically displays residual hoop and radial stress emanating from the hole at four different orthogonal angles; 
         FIG. 10A  and  FIG. 10B  illustrate exploded and cutaway views of a representative embodiment of installation tool  200  of the present disclosure; 
         FIG. 11A  depicts force sensor  222  connected to a digital read out device configured to record pressure measurements throughout the installation process; 
         FIG. 11B ,  FIG. 11C  illustrate the digital readout device, in various embodiments, may record pressure measurements several times per second (e.g., at least 60 times per second) so as to accurately capture one or both of a maximum and total force applied by installation tool  200  to fastener  100  during installation; 
         FIG. 11D  illustrates total area under the curve of all the force applied during installation; 
         FIG. 12A ,  FIG. 12B ,  FIG. 12C ,  FIG. 12D ,  FIG. 12E ,  FIG. 12F , and  FIG. 12G  depict various steps of a representative process for installing fastener  100  with installation tool  200 ; 
         FIG. 13A  and  FIG. 13B  illustrate perspective and cutaway views of a representative embodiment of a force measurement tool  300  for measuring a force associated with installing fastener  100  and/or expanding hole  12 ; 
         FIG. 14A ,  FIG. 14B  and  FIG. 14C  illustrate schematic views of adapter  300  configured for use with various existing pullers  400 ; 
         FIG. 15A ,  FIG. 15B , and  FIG. 15C  depicts an installation tool  200  and adapter  300  provided with a radio frequency identification (RFID) reader, barcode reader, or similar device  510  configured to scan an RFID tag, barcode, or similar identifier  520  associated with each fastener  100 , structure  10 , and/or hole  12 , depending on the particular embodiment; 
         FIG. 16A  and  FIG. 16B  illustrates an installation tool  200  or adapter  300  equipped with a device  600  for automatically marking structure  10  near fastener  100  (or fastener  100  itself) with at least an indication of whether the installation passed or failed. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are directed to fasteners  100  for securing a bolt  14  inserted through a hole  12  in a structure  10 . In particular, fasteners  100  of the present disclosure may be configured for attachment to an opposing surface of structure  10  such that fastener  100  may automatically receive and secure a distal portion of bolt  14  extending through hole  12 . As configured, a person installing bolt  14  from a proximal side of structure  10  is not required to physically access the opposing side of structure  10  in order to secure bolt  14  in place within hole  12  of structure  10 . While sometimes described in the context of aircraft structures herein, it should be noted that the present fastener  100  may be used or adapted for use in any industry for cold working a hole and retaining a bolt in any suitable structure. 
     Fasteners  100  of the present disclosure satisfy a long-felt need for robust fasteners that are capable of remaining securely attached to structure  10 , while minimizing a diameter of hole  12  required for accommodating the fastener and bolt  14  there within. More specifically, embodiments of fasteners  100  leverage a combination of design features to meet these needs, including a one-piece construction featuring a very thin-walled bushing that may be expanded within hole  12  without damage to securely anchor fastener  100  to structure  10  along with an optional adhesive. As configured, fasteners  100  of the present disclosure exhibit high-torque out performance while minimizing any required hole expansion (and thereby preserving edge distance). Related benefits include reduced maintenance requirements and increased lifespan of structure  10 , as loads in structure  10  can be distributed between more holes/fasteners, and cracks or corrosion can be repaired multiple times before exceeding permissible edge distance limitations due to the minimal additional hole expansion required for accommodating the thin-walled bushing of fasteners  100 , as later described in more detail. 
     Embodiments of the present disclosure are further directed to an installation tool  200  for installing fasteners  100  (and other similar fasteners). In particular, installation tool  200  may automatically measure the mandrel pull force applied during the installation of each fastener  100  and immediately provide a technician using installation tool  200  with feedback as to whether the installation was performed within specification (i.e., passed/failed), which can in turn reduce installation and maintenance times, and improve reliability and part lifespan, amongst other benefits. Further, installation tool  200  may record the installation force measurements for each fastener  100  that is installed, and thereby create an auditable record that may be analyzed to improve installation and maintenance protocols, and to reduce the need for supervision over the installation process, amongst other benefits. Still further, some embodiments of installation tool  200  may be configured to associate the measured pull force with a location of each corresponding fastener  100  on structure  10 , thereby facilitating efforts to locate individual fasteners that may need repair, replacement, or inspection, and also allowing for location-based analysis of the associated auditable record, as later described in more detail. 
     Rivetless Fastener  100   
       FIG. 1  illustrates a perspective view of a representative embodiment of fastener  100  of the present disclosure. Fastener  100  may generally include a retainer  110  and a bushing  120 , which may be integrally formed with one another for a one-piece construction. Generally speaking, retainer  110  may be configured for securing a distal portion of bolt  14  inserted through hole  12 , and bushing  120  may be configured for insertion into hole  12 , where it may be expanded to securely couple bushing  120  with hole  12 . In some embodiments, expansion of bushing  120  may securely couple bushing  120  with hole  12  via friction between the expanded bushing  120  and hole  12 , while in other embodiments, expansion of bushing  120  may serve to enhance the bond of an optional adhesive  130  between bushing  120  and hole  12 . Whether by friction, an enhanced adhesive bond, or a combination thereof, expansion of bushing  120  may serve to securely anchor retainer  110  to the portion of structure  10  surrounding hole  12  due to the one-piece construction of fastener  100 , as later described in more detail. The thin wall of bushing  120  may minimize the amount of hole expansion necessary to accommodate bushing  120 , while coldworking expansion of bushing  120  and the adhesive bond generated by adhesive  130  may combine to secure bushing  120  strongly within hole  12  without buckling or otherwise damaging the thin wall of bushing  120 . The one piece construction of the present fastener, in turn, results in bushing  120  helping to anchor fastener  100  securely in place. 
     Retainer  110   
       FIG. 2A ,  FIG. 2B ,  FIG. 2C , and  FIG. 2D  illustrate front, side, top, and bottom views of fastener  100 . In the representative embodiment shown, retainer  110  of fastener  100  may generally include a bottom surface  112  configured for positioning against a surface of structure  10  surrounding hole  12 , and a coupler  114  for attaching a nut  116  for securing a distal portion of bolt  14  extending from hole  12 . 
     Bottom surface  112  of retainer  110 , in various embodiments, may be shaped to provide a flush interface against the surface of structure  10  surrounding hole  12 . For example, in an embodiment, bottom surface  112  may be flat so as to provide a flush interface with structures  10  having a flat surface surrounding hole  12 . Similarly, in another embodiment, bottom surface  112  may have a curvature designed to lay flush with structures  10  having a curved surface surrounding hole  12 . More specifically, bottom surface  112 , in an embodiment, may have a concave curvature dimensioned to provide a flush interface with a similarly dimensioned convex surface surrounding hole  12 , whereas in another embodiment, bottom surface  112  may have a convex curvature dimensioned to provide a flush interface with a similarly dimensioned concave surface surrounding hole  12 . While bottom surface  112  of retainer  110  is preferably designed to provide a flush interface with the surface of structure  10  surrounding hole  12 , it should be appreciated that embodiments of fastener  100  having a non-flush interface between bottom surface  112  and the surface of structure  10  surrounding hole  12  may perform similarly in many cases and that the present disclosure is not intended to be limited as such. 
     Coupler  114  of retainer  110 , in various embodiments, may include any suitable mechanism or structural feature configured for holding nut  116  in alignment with bushing  120 . In particular, coupler  114  may hold nut  116  such that a longitudinal axis of nut  116  is substantially aligned with a longitudinal axis of bushing  120  (both vertical in  FIG. 2A ) such that when bolt  14  is inserted into bushing  120 , the distal portion of bolt  14  exits bushing  120  in axial alignment with the central hole of nut  116 . As configured, coupler  114  may allow for nuts  116  of various sizes and designs to be used with a given fastener  100 , and can be swapped out without the need for removing fastener  100  from structure  10 . In the embodiment shown, coupler  114  includes a groove  115  for receiving a spring clip  115   a  configured to secure nut  116  on fastener  100 , as shown in  FIG. 2E . It should be recognized that groove  115  is but one example of a suitable coupler  114  for holding nut  116  in alignment with bushing  120 , and that the present disclosure is not intended to be limited to any particular design of coupler  114 . In another embodiment (not shown), nut  116  may be formed as part of retainer  110  or otherwise attached thereto. Nut  116 , however it may be associated with retainer  110 , may be internally threaded in embodiments configured for securing bolts  114  equipped with external threading. 
     Bushing  120   
     Still referring to  FIG. 2A ,  FIG. 2B ,  FIG. 2C , and  FIG. 2D , in the representative embodiment shown, bushing  120  of fastener  100  may extend from bottom surface  122  of retainer  110 , and may be shaped to conform with a shape of hole  12  in structure  10 . In a representative embodiment, bushing  120  may substantially cylindrical and thereby fit into a standard hole produced by a cylindrical drill bit. The length of bushing  120 , in various embodiments, may be configured to substantially match the depth of hole  12  in structure  10  and may be substantially hollow to accommodate bolt  14  therethrough. 
     As later described in more detail, it may be advantageous to minimize the outer diameter of bushing  120  so as to minimize a diameter of hole  12  required for accommodating bushing  120  and bolt  14  there within. Bushing  120 , in various embodiments, may generally include an outer surface  122  and an inner surface  124  separated by a thickness dimension  126  (hereinafter referred to as “wall thickness  126 ”), as shown. Outer surface  122  and inner surface  124 , in various embodiments, may define an outer diameter and an inner diameter of the substantially cylindrical and hollow body of bushing  120 . Thus, in various embodiments, it may be preferable to minimize the inner diameter and wall thickness  126  of bushing  120 . 
     In operation, bolt  14  may extend through the hollow portion of bushing  120  defined by inner surface  124  and thus, in various embodiments, inner surface  124  may be dimensioned to accommodate an outer diameter of bolt  14 . Accordingly, in various embodiments, inner surface  124  may be dimensioned to match or only slightly exceed the outer diameter of bolt  112 . That said, because bushing  120  may be expanded during the installation process, in various embodiments, inner surface  124  may be dimensioned to have a diameter slightly smaller than the outer diameter of the particular bolt  14  being used in a given application. For example, if the installation process calls for a 3.5% expansion of bushing  120  during installation, inner surface  124  may be dimensioned to have a proportionally smaller diameter (e.g., about 1.5% to about 4.5% smaller) and still accommodate bolt  14  once fastener  100  is installed. One of ordinary skill in the art will recognize an appropriate inner diameter of bushing  120  for accommodating bolt  14  as installed in structure  10  in accordance with the teachings of the present disclosure. 
     As previously noted, it may also be advantageous to minimize wall thickness  126  in an effort to minimize the outer diameter of bushing  120 . That said, if wall thickness  126  is too small, bushing  120  may not exhibit the structural strength required for expansion and various loads experienced by structure  10  without bushing  120  being damaged. Accordingly, in various embodiments, bushing  120  may be provided with a wall thickness  126  optimized for both of the aforementioned considerations—namely, a minimum wall thickness required to withstand an expected amount of expansion and applied loads for a given application. Based on the later described analysis and testing of various designs and materials (e.g., machined 17-4 stainless steel, stainless steel alloys, titanium), bushing  120  may exhibit the requisite structural integrity with wall thicknesses  126  ranging from about 0.005 inches to about 0.030 inches and greater. Accordingly, in various embodiments, bushing  120  may have a wall thickness ranging from about 0.005 inches to about 0.030 inches, and more preferably, about 0.010 inches in an embodiment. Of course, one of ordinary skill in the art following the teachings of the present disclosure will recognize an appropriate wall thickness  126  for satisfying the above referenced factors for a given application without undue experimentation. 
     Outer surface  122 , as previously noted, may define an outer diameter of bushing  120  and, in some embodiments (e.g., no intervening adhesive  130 ), may securely couple with the inner wall of hole  12  via friction fit. To that end, outer surface  122 , in various embodiments, may include texturing (not shown) configured to increase a coefficient of friction of outer surface  122  and thereby enhance the friction fit with hole  12 . For example, outer surface  122  may be provided with raised bumps, raised cross-hatching, or other protrusions for enhancing its frictional coefficient. Additionally or alternatively, outer surface  122 , in various embodiments, may be provided with texturing configured to help retain optional adhesive  130  thereon. Likewise, bottom surface  122  of retainer  110  may be provided with texturing for either or both of the aforementioned purposes as well (noting that bottom surface  122  may engage the surface of structure  10  surrounding hole  12 , rather than the inner surface of hole  12  as with outer surface  122  of bushing  120 ). While texturing may increase friction and help to anchor fastener  100  in place, one of ordinary skill in the art will recognize that, in certain applications, texturing could cause damage to the inner surface of hole  12  and perhaps unfavorably reduce the life extension benefits of coldworking. One of ordinary skill in the art will recognize without undue experimentation a suitable texturing (if any) for enhancing anchoring while maintaining desired part life properties. 
     Manufacturing and Construction of Fastener  100   
     Fastener  100 , in various embodiments, may be constructed of any material suitable for attaching to structure  10  and retaining bolt  14  in hole  12  in accordance with the teachings set forth in the present disclosure. In various embodiments, fastener  100  may be constructed of a metallic material having high structural strength to avoid ripping or buckling during installation and under applied loads, but malleable enough for being expanded within hole  12  as later described. Representative examples of such a metallic material include, without limitation, stainless steel (e.g., 17-4 grade, Custom 465 grade), titanium, and their alloys. One of ordinary skill in the art will recognize other suitable materials without departing from the scope of the present disclosure. 
     Retainer  110  and bushing  120 , in various embodiments, may be integrally formed with one another and thereby provide fastener  100  with a one-piece construction. As later described in more detail, this one-piece construction may allow bushing  120  to serve in part as an anchor for securing retainer  110  in position against the surface of structure  10  surrounding hole  12 . 
     To that end, bushing  120  may be machined from a single piece of metallic material in accordance with various embodiments. For example, a representative manufacturing approach may begin with a stock of desired material, such as the material described above. The stock may be machined first to rough size and shape, and then to final dimensions, using a lathe, CNC lathe, Swiss lathe, CNC milling machine, CNC machining center, or other suitable tool(s). The dimensioned material may be inspected for dimensional accuracy, and any burrs and rough edges may be removed using a tumbling machine, mechanical sanding, manual sanding, mechanical filing, manual filing, or any other suitable tool(s) and technique(s). Next, it may be cleaned to remove any oils, lubricants, cutting fluid, or other contaminates that may have been present on the original stock or introduced during the manufacturing process, and any foreign metal particles and other debris may be removed such as tool steel and metal shavings that may have become embedded in the surface. Fastener  100  may be finished with one or more coatings for preserving the material (e.g., preventing corrosion, oxidation) via chemical cleaning, chemical etching, passivation, anodizing, galvanizing, electroplating, powder coating, or other suitable finishing process(s). 
     Installing Fastener  100  with Cold Expansion 
       FIG. 3A ,  FIG. 3B , and  FIG. 3C  illustrate top, side, and cross-sectional views of a representative embodiment of fastener  100  as installed in hole  12  of structure  10 . Fastener  100 , in various embodiments, may be positioned on an opposing side of structure  10  from which bolt  14  is inserted into hole  12  so as to receive the distal end of bolt  14  when inserted. As best seen in the cross-sectional view of  FIG. 3C , bushing  120  resides within hole  12  and bottom surface  122  is positioned against the surface of structure  10  surrounding hole  12 . 
     Generally speaking, fastener  100  may be installed on structure  10  in accordance with standard coldworking processes known in the art. For example, hole  12  may be prepared (e.g., drilled, reamed, and cleaned), and fastener  100  positioned with bushing  120  inserted in hole  12  and bottom surface  122  of retainer  120  positioned against the surface of structure  10  surrounding hole  12 , as described above. Next, a split-sleeve may be attached to an appropriately-sized tapered mandrel  20  and inserted into bushing  120  through retainer  110 . The tapered mandrel  20  may be attached to a puller tool (e.g, manual, hydraulic, electrical (wired or battery-powered), etc.) and pulled to expand bushing  120  within hole  12 . Absent any optional adhesive  130  between bushing  120  and hole  12 , expansion of bushing  120  may securely couple bushing  120  with hole  12  via a friction fit between outer surface  122  of bushing  120  and the inner surface of hole  12 . That said, frictional coupling may be present in embodiments in which adhesive  130  is used, but is not present throughout the entire interface between bushing  120  and hole  12 , such as if some of the adhesive squeezed out during expansion of bushing  120  or if adhesive  130  were only applied to portions of outer surface  122  of bushing  120 . In such situations, portions of outer surface  122  of bushing  120  may be in direct contact with the inner surface of hole  12 , and thus may provide for friction-based coupling in these areas. The one-piece construction of the present fastener  100 , in turn, results in the expanded bushing  120  helping to anchor retainer  110  against the surface of structure  10  surrounding hole  12 . 
     Notably though, while split sleeves are typically used to reduce the amount of pulling force needed to expand a traditional bushing (i.e., a bushing having a wall thickness of 0.050 inches or greater), testing shows that the split sleeve serves to protect the relatively thin-walled bushings  120  of the present fastener  100  during the expansion process. In particular, certain prototypes of fastener  100  made of Titanium, Custom 465 grade stainless steel, and 17-4 grade stainless steel, and having wall thicknesses  126  of 0.010 inches, were damaged (i.e., ripped) during installation when a split sleeve was not used. Thus, the combination of a split-sleeve and thin-walled bushings (i.e., those having wall thicknesses less than about 0.030 inches) provided the unexpected result of protecting the bushing from damage during installation, and may allow for fastener  100  to be expanded further than it otherwise could be (e.g., as much as about 4.5% or more) using traditional cold expansion techniques without incurring damage. 
     Installing Fastener  100  with Cold Expansion and Adhesive  130   
       FIG. 4A  and  FIG. 4B  illustrate another approach for installing fastener  100  on structure  10  in accordance with a representative embodiment of the present disclosure. In the approach shown, an adhesive  130  may be applied to fastener  100  and/or contacted portions of structure  10  to form an adhesive bond between fastener  100  and structure  10 . Depending on the embodiment, the adhesive bond created by adhesive  130  may serve to securely couple bushing  120  with hole  12  and/or retainer  110  with surface  10 , and thereby prevent fastener  100  from torqueing-out or otherwise spinning out of hole  12 , and falling off structure  10 . As configured, well in excess of about 165 inch-pounds to about 175 inch-pounds of torque may be required to torque out various embodiments of fastener  100  from hole  12 . 
     Adhesive  130 , in various embodiments, may include any adhesive material suitable for forming an adhesive bond between components of fastener  100  and structure  10 , and may vary based at least in part on the particular materials and construction of fastener  10  and structure  10 . For example, many aircraft structures such as wings may be made of metallic or composite materials, and thus may have different properties requiring different adhesives to form a good bond. Representative adhesives  130  that may be suitable for metal-to-metal bonds may include, without limitation, Acrylic (e.g., PermaBond HM162) 2-part Methacrylate (e.g., Huntsman Araldite F305), 2-Part Polysulfide (e.g., PPG PS890) and 2-part Epoxy (e.g., 3M Scotch Weld 405), while representative adhesives  130  that may be suitable for metal-to-composited bonds may include, without limitation, Master Bond EP31 two component epoxy, Supreme 10HT one component epoxy, Master Bond&#39;s EP21TDCHT flexibilized epoxy adhesive, 3M™ Scotch-Weld™ Acrylic Adhesive DP8410NS, 3M™ Scotch-Weld™ Multi-Material Composite Urethane Adhesive DP6310NS, and the like. 
     Referring to  FIG. 4B , in various embodiments, adhesive  130  may be applied to one or both of retainer  110  and bushing  120 . In particular, in an embodiment, adhesive  130  may be applied to bottom surface  112  of retainer  110  so as to provide an adhesive bond at the interface between bottom surface  112  and the surface of structure  10  surrounding hole  12 . This adhesive bond may provide a direct coupling between retainer  110  and structure  10 , as opposed to relying solely on the indirect coupling of retainer  110  to structure  10  via the coupling of the integrally-attached bushing  120  and the inner surface of hole  12 . 
     Additionally or alternatively, in an embodiment, adhesive  130  may be applied to outer surface  122  of bushing  120  so as to provide an adhesive bond at the interface between outer surface  122  and the inner surface of hole  12 . Expansion of bushing  120  may enhance this adhesive bond, in various embodiments, by centering bushing  120  within hole  12  and reducing any gap between outer surface  122  of bushing  120  and the inner surface of hole  12 . Centering bushing  120  with hole  12  and reducing this gap may serve to thin the bond line provided by the adhesive between outer surface  122  of bushing  120  and the inner surface of hole  12 , and thus enhance the bond provided by adhesive  130 . 
     In some embodiments, bushing  120  may be securely coupled with hole  12  entirely or primarily by the adhesive bond provided by adhesive  130 . This may be particularly characteristic of (but not limited to) installations of fastener  100  in composite structures  10 , as composite materials tend to be more brittle than metallic materials, and thus may crack rather than compress if bushing  120  and hole  12  are expanded significantly. That said, in various embodiments, bushing  120  may still be expanded to enhance the bond created by adhesive  130  between bushing  120  and hole  12 , and thereby provide a significant improvement compared with the bond that may otherwise be generated by adhesive  130  absent expansion of bushing  120 . As noted above, in other embodiments, adhesive  130  may not be present throughout the entire interface between bushing  120  and hole  12  and, as such, those portions of bushing  120  and hole  12  that are in direct contact may be coupled at least in part via friction, and those portions separated by adhesive  130  may be coupled at least in part via adhesive bond, which may notably be enhanced by the expansion process. 
     Notably, the enhanced adhesive bond created by adhesive  130  between expanded fastener  100  and structure  10  may allow for a relatively thinner-walled fastener  100  to be used, all without sacrificing the overall strength of the attachment between fastener  100  and structure  10 . Such an approach may be desirable, for example, in situations where it is of greater importance to minimize the diameter of hole  12  versus maximize the strength of the attachment of fastener  100  to structure  10 . In particular, the adhesive bond created by adhesive  130  may to offload or eliminate the degree to which friction fit must contribute towards anchoring fastener  100  to structure  10 , thereby reducing the amount of expansion required and thus allowing for a relatively thinner wall thickness  126  to be used without incurring damage. For example, in such situations, a fastener  100  with a relatively smaller wall thickness  126  (e.g., about 0.010 inches) may be utilized, and expanded to a lesser degree (e.g., between about 1.5% and about 3.5%) to produce a relatively weaker or no friction fit. The weaker friction or lack of friction would; however, be compensated for by the adhesive bond created by adhesive  130  (and enhanced by small expansion of bushing  120 ), and thus the overall strength of the attachment of fastener  100  to structure  10  would be maintained, and the diameter of hole  12  reduced relative to using a thicker-walled fastener. Stated otherwise, the thin wall thickness  126  may minimize the amount of hole  12  expansion necessary to accommodate bushing  120 , while coldworking and adhesive  130  may combine to secure bushing  120  strongly within hole  12  without buckling or otherwise damaging the thin wall of bushing  120 . 
     As noted above, it should be noted that adhesive  130  may play a significant role in attaching fastener  100  to structure  10 , especially when structure  10  is formed of a composite material. Composite materials used in aircraft structures, for example, have little to no plasticity compared with metal structures, and thus it may not be possible to use high levels of expansion to secure bushing  120  to the sides of hole  12 . In such cases, the friction fit may be relatively weak. This issue may be overcome, in some embodiments, by applying adhesive  130  to outer surface  122  of bushing  124  such that expansion of bushing  120 , albeit a small amount, causes adhesive  130  to seal and bond bushing  120  uniformly with the sides of hole  12 . 
     Conversely, in some situations it may be of greater importance to ensure that fastener  100  is very strongly attached to structure  10  versus minimizing the diameter of hole  12 . In such situations, a fastener  100  with a relatively larger wall thickness  126  (e.g., about 0.030 inches, but still significantly smaller than the traditional 0.050″ wall thickness of existing nut plates) may be utilized, with or without adhesive  130 , and expanded significantly (e.g., by about 3.5% to about 5%) without damaging bushing  120  due to its relatively larger thickness. If adhesive  130  is used, the resulting adhesive bond as enhanced by the expansion of bushing  120 , may be even stronger than that generated by the smaller expansions previously described. Additionally or alternatively, the resulting adhesive bond may supplement the strong anchoring effect provided by friction fit between any portions of bushing  120  and hole  12  that may be in direct contact, such that fastener  100  is very strongly secured to structure  10 . 
     It should be recognized that adhesive  130  may additionally or alternatively be applied to corresponding portions of structure  10  (and hole  12 ) in contact with these portions of fastener  100  to similar effect. 
     Referring now to  FIG. 4C , in an embodiment, fastener  100  may include one or more holes  118  extending through retainer  110  for enhancing the adhesive bond between retainer  110  and the surface of structure  10  surrounding hole  12 . Hole(s)  118 , shown here as extending through a bottom portion of retainer  110  including bottom surface  122 , may be configured to allow adhesive  130  to form a bond in a different dimension (e.g., vertical) to strengthen the adhesive bond between retainer  110  and the surface of structure  10  surrounding hole  12 . 
     Adhesive  130 , in some embodiments, may be applied by a technician during the installation process (e.g., by brushing, spraying, rolling, or dipping) while, in other embodiments, adhesive  130  may be applied at the time of manufacturing (e.g., at the factory before fasteners  100  are even shipped to technicians for installation). In the latter embodiments, adhesive  130  may, for example, be applied to fastener  100  and covered with protective material configured to be peeled away by a technician just prior to installation. In another example, adhesive  130  may be configured to be encapsulated and pressure activated, meaning it is released or becomes sticky in response to applied pressure. As configured, an encapsulated pressure-activated adhesive  130  may be applied at the time of manufacturing, transported and handled without creating a mess, and activated to form the adhesive bond when pressed against structure  10  (e.g., pressed against the inner wall of hole  12  during the expansion of bushing  120  and/or pressed against the surface of structure  10  surrounding hole  12  during installation or when a technician tightens down bolt  14 ), as shown in  FIG. 4B . Representative examples of a pressure-activated adhesive  130  may include, without limitation, Microencapsulated Acrylates (e.g., precote 80), Epoxy (e.g., 3M 2353), Acrylic (e.g., Loctite 2040). It should be appreciated that, generally speaking, embodiments in which adhesive  130  is applied during manufacturing as opposed to during installation may reduce the effort, time, and cost required for a technician to install fastener  100  on structure  10 . 
     Alternative Installation Techniques 
     Fastener  100 , in various embodiments, may be installed according to several additional approaches. For example, in an embodiment, a high-frequency hammer, hydraulic, or electrical puller may be used to pull mandrel  20  through hole  12 . This method may greatly reduce the pull force required to pull mandrel  20  through hole  12 . In another embodiment, mandrel  20  may be attached to a small gear box having a favorable gear ratio to facilitate a user in pulling mandrel  20  through hole  12 . The gears of the small gear box may be engaged by a manual wrench, an electric drill, a pneumatic drill, or any other suitable mechanism. Further, mandrel  20  could be provided with notches oriented substantially perpendicular to a longitudinal axis of mandrel  20  in order to engage with the gears. This method may greatly reduce the force required to pull mandrel  20  through hole  12 . In yet another embodiment, two opposing threaded rods may be arranged in parallel and engage a threaded mandrel  20  to help pull mandrel  20  through hole  12 . The parallel threaded rods may be engaged by a manual wrench, electric drill, or pneumatic drill and, in one embodiment, may be contained in an enclosure. Fastener  100 , along with similar nut plates and other fasteners, may also be installed using installation tool  200  according to various embodiments of the present disclosure, as later described in more detail. 
     Potential Advantages of Fastener  100   
       FIG. 5  is a chart comparing aspects of fastener  100  of the present disclosure with those of existing nut plates. Each of the existing nut plate designs suffers from one or more disadvantages compared with fastener  100 . 
     For example, referring to the second row of the chart of  FIG. 5 , one type of existing nut plate is configured to be bonded to the surface of structure  10 . Because these nut plates lack a barrel or similar structure extending into hole  12 , they are not anchored within hole  12  as fastener  100  is. Instead, these nut plates rely solely on adhesion with the surface of hole  12 , and thus are prone to falling off. Further, any coldworking to repair hole  12  is done separately from installation of such fasteners, thereby increasing the time of the repair. 
     Moving on to the third row of the chart of  FIG. 5 , another type of existing nut plate includes a thin-walled “barrel” (e.g., 0.008 inches thick) that at first glance appears similar to bushing  120  of fastener  100 , but its “barrel” is configured to serve more as a protective sleeve during installation. As such, this sleeve is not fixedly attached to its retainer (resulting in a multi-piece construction), and the sleeve does not create as strong of a friction fit with the interior of hole  12  as the expanded bushing  120  of fastener  100  does. As a result, the sleeve of this type of existing nut plate does not serve to anchor itself within hole  12 , and thus—by extension—does not serve to anchor the retainer to structure  10  in the way that fastener  100  does. 
     Referring now to the fourth and final row of the chart of  FIG. 5 , another type of existing nut plate includes a thick-walled barrel (e.g., 0.040-0.065+ inches thick), similar to that later shown alongside fastener  100  in  FIG. 6A  and  FIG. 6B . Due to their thick walls, these nut plates are capable of being cold worked to high levels of expansion, and thus rely on the resulting friction fit between the expanded barrel and hole  12  for securement on structure  10 . As later described in more detail, large diameter holes  12  are required to accommodate these thick-walled nut plates, and thus holes must be drilled farther apart from one another and the edges of structure  10 . This reduces the number of times each hole can be repaired before the edge of the holes exceeds minimum edge distance limitations, as later described in more detail. 
     Turning now to the first row of the chart, embodiments of fastener  100  may provide for several advantages over existing nut plates and similar fasteners. In particular, various embodiments of fastener  100  may be lighter, less expensive, more reliable, and both quicker and easier to install than existing rivetless nut plates and similar fasteners. In fact, using fasteners  100  of the present disclosure on a military aircraft (e.g., the F-18 Hornet, F-35 Lightning, and MQ-4C Triton, and RQ-4 Global Hawk) instead of using existing nut plates, is estimated save upwards of $100,000 per aircraft. More specifically, embodiments of fastener  100  may provide at least one or more of the following advantages over existing nut plates and similar fasteners: 
     1) Fatigue Performance 
     Fastener  100  is compatible with coldworking techniques, which can be used to repair cracks around hole  12  and to prevent new cracks from forming around hole  12 . Nut plates and similar fasteners lacking bushing  120  (e.g., those that simply adhere to the surface of structure  10 ) cannot be cold-worked in hole  12  like fastener  100 , and thus do not enjoy the corresponding benefits of crack repair and prevention. When combined with a cold working process, as is the case in various embodiments of the present fasteners and installation methods, the incidence of fatigue cracks can be further mitigated, also contributing to increased structure longevity. 
     2) Edge Distance 
     After fatigue cracks have been detected structure  10 , the fatigue cracks are typically be removed by enlarging holes  12 . In some cases, the damaged holes  12  may be cold worked to extend the life of the newly formed holes  12  and surrounding material. It is often necessary, especially with fasteners having thick barrel walls, to enlarge damaged holes  12  by quite a bit to accommodate the replacement fastener. Oftentimes the amount the damaged hole  12  needs to be enlarged to sufficiently eliminate the cracks is less than the amount the damaged hole  12  needs to be enlarged to fit in a fastener with a relatively thick barrel wall. 
     Reduced edge distance can prove problematic especially in holes  12  situated close to an edge of structure  10 . As the distance between the center of hole  12  and the edge of structure  10  (i.e., edge distance) decreases, the chance of structure  10  failing in that area increases. Generally speaking, from the standpoint of preserving structural integrity, it is ideal to keep edge distance above about 2, though in some cases about 1.5 is acceptable. If edge distance is already below 2 and the damaged hole  12  needs to be enlarged to repair fatigue cracks, the edge distance will be further reduced. Eventually a point is reached where hole  12  cannot be safely enlarged any further, oftentimes leading to the entire structure  10  having to be replaced or undergo more significant repairs. 
     The thin wall bushing  120  of fastener  100  may help to mitigate reductions in edge distance resulting from repairs. For example, while it may be necessary to enlarge hole  12  to the extent that edge distance is reduced to 1.5 in order to accommodate relatively thick wall fastener, that same hole may only need to be enlarged to the extent that edge distance is reduced only to 1.8 or 1.7 in order for the enlarged hole  12  to accommodate the relatively thin wall of fasteners  100 . 
     In particular, hole  12  must be drilled or expanded to have sufficient diameter to accommodate a given bolt  14  and fastener within hole  12 . For a given sized bolt  14 , hole  12  must have a larger diameter to accommodate fasteners with thicker walls, whereas fasteners with thinner walls can be accommodated in smaller diameter holes  12 . Because fasteners  100  of the present disclosure feature thinner walls than those of some existing nut plates and similar fasteners, they require relatively smaller holes  12 . As such, during new builds, the corresponding holes  12  may be drilled closer to the edges of structure  10  without violating minimum edge distance requirements. Likewise, the corresponding holes  12  can be repaired using coldworking multiple times before edge distance becomes so small that structure  10  must be replaced. Accordingly, fastener  100  can be used in many situations where others cannot due to edge distance requirements, and as a corollary, can lengthen the lifespan of structure  10  by allowing for repairs near edges instead of having to replace structure  10 . Likewise, the reduced edge distance impact provided by fasteners  100  may allow for replacement of other types of fasteners on existing structures that do not perform as well. For example, the F-35 utilizes surface fasteners (e.g., Click Bond nutplates, which do not extend into the hole but rather sit only on the surface of the structure) that tend to fall off often; however, because edge distance on the F-35 aircraft is often very tight to acceptable limits, it may not be possible to replace these surface fasteners with existing thicker-walled fasteners because edge distance would be reduced beyond acceptable limits. The thin-walled fasteners of the present disclosure, on the other hand, may be suitable for replacing these surface fasteners due to reduced edge distance impact. Further, in the context of a new build instead of repair, by minimizing hole diameter and thus reducing edge distance constraints, designers have more flexibility in positioning holes wherever they wish to on the structure. 
     For example, consider the representative embodiments of fastener  100  and a thick-walled nut plate shown in  FIG. 6A  and  FIG. 6B . Bushing  120  of fastener  100  has a 0.010 inch wall thickness  126 , while the barrel of the representative thick-walled nut plate has a thickness of about 0.050 inches, or five times that of fastener  100 . 
       FIG. 7A ,  FIG. 7B , and  FIG. 7C , illustrate the variations in required hole diameters and resulting edge distances of the thin-walled fastener  100  and a representative thick-walled nut plate presented in  FIG. 6A  and  FIG. 6B . In particular,  FIG. 7A  represents a baseline, in which hole  12  has experienced cracks or corrosion and is in need of repair. Pre-repair, original hole  12  has a 0.250 inch diameter and is situated with its center 0.500 inches from the edge of structure  10 , resulting in its outer edge being 0.375 inches from the edge of structure  10 . As configured, original hole  12  has an edge distance of 2.0. For clarity, edge distance, or “e/D”, is a metric used to express how close a hole is to the edge of a structure, in which “e” is the distance from the center of hole  12  to the edge of structure  10  and D is the diameter of hole  12 . In  FIG. 7A , e=0.500 inches and D=0.25 inches, so e/D=2.0. 
     Now, referring to  FIG. 7B , hole  12  has been drilled and coldworked during installation of a thin-walled fastener  100  of the present disclosure. The thin-walled fastener  100  has a wall thickness  126  of 0.010 inches, thus hole  12  had to be expanded by 0.02 inches total to accommodate the 0.010 inch increase in thickness on each side of bushing  120 . The resulting hole  12  is now 0.270 inches in diameter, and thus edge distance has been decreased by only 7.4%, from 2.0 in  FIG. 7A  to 1.852 in  FIG. 7B . 
     Comparatively, with reference now to  FIG. 7C , the thick walls of the nut plate required hole  12  to be expanded to a much greater extent as opposed that required when using the thin-walled fastener  100  of the present disclosure. In particular, thick-walled nut plate shown has a wall thickness of 0.050 inches (five times that of fastener  100 ), and thus the original hole  12  had to be expanded by 0.100 inches total to accommodate the 0.050 inch increase in thickness on each side of the barrel of the thick-walled nut plate. The resulting hole  12  is now 0.350 inches in diameter, and thus edge distance has been significantly decreased by 28.6%, from 2.0 in  FIG. 7A  to 1.428 in  FIG. 7C . 
     Stated otherwise, in the context of repairing structure  10 , the amount by which hole  12  needs to be expanded to accommodate a thin-walled fastener  100  of the present disclosure is significantly less than that required to accommodate a thick-walled nut plate. Despite the expansion of hole  12 , the outer edge of hole  12  remains relatively far away from the edge of structure  10 , and thus edge distance is mostly preserved when using a thin-walled fastener  100  of the present disclosure. Conversely, because hole  12  needs to be expanded more to accommodate a thick-walled nut plate, the outer edge of hole  12  ends up much closer to the edge of structure  10 . Thus edge distance is significantly reduced when using a thick-walled nut plate compared to thin-walled fastener  100 . 
     3) Reliability 
     Uniquely, fastener  100  combines the benefits of a thin-walled bushing  120  with the benefits of coldworking, all while anchoring securely to structure  10  such that fastener  100  does not easily fall off or spin out. 
     There has been a long-felt need for a fastener that can provide such a combination of benefits, yet nobody has found a suitable design until now. As shown in the experimental data appended to this document in Appendix B, the particular ranges of wall thickness and expansion % suitable that are suitable for achieving these benefits in combination in a one-piece design utilizing adhesives, was not easily determined. Seemingly obvious combinations of such parameters and modifications resulted in failures such as buckling of the fastener and/or low torque out values. 
     Anchoring may be accomplished through one or a combination of friction fit and enhanced adhesive bonding. Friction fit results from the coldworking process, and adhesive bonding may be enhanced by the coldworking process as bushing  120  is expanded. The coldworking process can be tailored (e.g., set to about 3.5% expansion) such that the cold expansion does not buckle the thin wall of the barrel, yet still expands the barrel enough to have one or a combination of: (i) a tight friction fit with the hole, and (ii) an enhanced adhesive bond, as further described above. The one-piece construction ensures that the friction fit and adhesive bond between the barrel and the hole serve to securely anchor the retainer portion. Adhesive at the interface between the retainer portion of the aircraft structure surface further enhances the reliability of the fastener. 
     4) Installation Time and Cost 
     As described above, fasteners  100  are easy and quickly installed. Existing equipment can be used, reducing tooling and training time. Down times (e.g., the amount of time an aircraft comprising structure  10  is out of service for associated repairs) are reduced due to the ease and speed at which holes  12  can be repaired with fasteners  100 , as well as due to the resulting increases in longevity of structure  10 . 
     Experimental Results 
     Torque-out tests were performed by PartWorks on aluminum specimens with either open holes or inserted RNPs made of either Titanium, or Stainless Alloys. Specimens were either ¼″ or ⅛″ thick. Our approach does not necessarily rely on large amounts of expansion for retention, so we are able to vary the expansion level to whatever is optimum for the material or application without being concerned about retention. 
     Constant amplitude fatigue testing was performed on coupons using a dogbone geometry, as shown in  FIG. 8 . The specimens incorporated a central hole, with several coupons also including rivetless nut plates (RNP) in the hole. PartWorks conducted all coupon machining and RNP installation. The net section applied stress was in the 25-35 ksi range with a target to failure below 200,000 cycles (which resulted in settling on 35 ksi) and a cyclic frequency to complete the testing within the period of performance. Cycles to failure was recorded. 
     By cold expanding the ultrathin-wall nut plate and establishing compressive residual stresses around the hole the data show that the resulting life from this process improves by an average of 7.7 times—greater than the life of the hole when the aircraft was new. This is a plot of maximum stress versus cycles to failure for all samples tested at a net-section stress of 35 ksi. The plot shows open-hole specimens in the as machined surface condition as the baseline for comparison. Open-hole samples with corrosion damage show a debit in life compared to the baseline samples, whereas corrosion damaged samples with the rivetless nut plate fastener show an increase in life (7.66× and 7.82×) compared to the as-machined baseline and the open-hole corroded data. Finally, the as machined samples with the rivetless nut plate fastener show a significant increase in life compared to the as machined open-hole specimen life. 
     This is the first time to our knowledge that anyone has demonstrated a solution to corroded aircraft structures that produces the same or better structural life enhancement, and furthermore, while maintaining acceptable edge distances and adequate torque out values through the use of ultra-thin wall nut plates with adhesives. 
       FIG. 9A  graphically displays results of several constant amplitude Fatigue Life Tests performed by University of Dayton Research Institute in graphical form, with a constant stress level of 35 KSI. It can be clearly seen from this graph that the fatigue life of corroded samples, which start at a deficit to new/virgin, open hole samples, after installation of two RNP fasteners actually exceeded the fatigue life of the new/virgin open hole samples in both cases, with nearly identical results, both before and after. This is the first time to our knowledge this significant result has been demonstrated. 
     Table I below represents the data in  FIG. 9A  in tabular form. It is clear from this data how consistent the fatigue life results were between the two tests on corroded samples with inserts: 7.66 and 7.82 times improvements versus the fatigue life of corroded open hole samples. This is well above the target improvement of 5 times improvement and as shown in  FIG. 9A  is enough improvement to exceed the fatigue life of as-new open hole samples. 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
             
               
                   
                 TABLE I 
               
             
            
               
                   
                   
               
               
                   
                   
                   
                   
                 Outside 
                 Stress 
                 Stress Ratio 
                   
                   
                   
                   
               
               
                   
                 Parts 
                 Width 
                 Thickness 
                 Hole Dia. 
                 Level 
                 0.1 (lbf) 
                 Frequency 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 UD I.D. # 
                 Works I.D. 
                 (in) 
                 (in) 
                 (in) 
                 (ksi) 
                 Min 
                 Max 
                 (Hz) 
                 Start Date 
                 End Date 
                 Cycles 
                 Ratio 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 STL563-7 
                 Corroded/ 
                 1.00000 
                 0.24930 
                 0.2510 
                 35 
                 654 
                 6535 
                 20 
                 19 Feb. 2018 
                 19 Feb. 2018 
                 7,754 
                  7.147 
               
               
                   
                 Open Hole 
               
               
                 STL563-8 
                 Corroded/ 
                 0.99750 
                 0.25330 
                 0.2540 
                 35 
                 659 
                 6591 
                 20 
                 19 Feb. 2018 
                 19 Feb. 2018 
                 6,539 
               
               
                   
                 Open Hole 
               
               
                 STL563-15 
                 Corroded/ 
                 1.0037 
                 0.2468 
                 0.2790 
                 35 
                 626 
                 6260 
                 20 
                 16 Feb. 2018 
                 16 Feb. 2018 
                 54,711 
                 7.66 
               
               
                   
                 Insert 
               
               
                 STL563-16 
                 Corroded/ 
                 1.0008 
                 0.2453 
                 0.2785 
                 35 
                 620 
                 6202 
                 20 
                 16 Feb. 2018 
                 16 Feb. 2018 
                 55,858 
                 7.82 
               
               
                   
                 Insert 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 (target 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 is 5-10 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 times) 
               
               
                   
                 CORROSION 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 Average 
                 7.74 
               
               
                   
                 RATIO 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 life 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 Improvement 
               
               
                   
               
            
           
         
       
     
     Spectrum testing was also performed, here using the F- 18  wing root bending spectrum. This is derived from millions of flight hours of F- 18  fleet usage and is adjusted to represent the  90 th percentile of usage severity, as is the standard Navy design practice. This spectrum has the high peak stresses that can negatively affect the life improvement of cold worked holes by exceeding the local yield stress and reducing the compressive residual stress imparted by the cold working process. This is a common problem with short edge distance holes and is one of the reasons we have selected the thin wall concept, to avoid the short edge distance situation. 
     The table below shows the results of constant amplitude fatigue life testing on two uncorroded samples before and after installation of the fastener (insert). It demonstrates an increase in fatigue life with the 0.010″ thin wall fastener of more than five times its original life. This is the first demonstration to our knowledge that thin wall fasteners can still meet or exceed life extension benefits heretofore only available with thicker wall (0.040 and above) fasteners, with all their benefits of improved edge distance, lower net stress, given constant applied load and part weight, and flexible use in composites. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE II 
               
               
                   
                   
               
               
                   
                 LIFE 
                 AVERAGE 
                 RATIO 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Spectrum/Open Hole (s1) 
                 210,346 
                 199,834 
                 5.57 
               
               
                 Spectrum/Open Hole (s2) 
                 189,322 
               
               
                 Spectrum/Insert (s1) 
                 970,256 
                 1,113,228 
               
               
                 Spectrum/Insert (s2) 
                 1,256,200 
               
               
                   
               
            
           
         
       
     
       FIG. 9B  is a graphical display of residual hoop and radial stress emanating from the hole at four different orthogonal angles. This graph significantly demonstrates a similar pattern of stress found in prior art. This is significant because it demonstrates that using a thin walled nutplate provides the same pattern of residual stress in samples as previous generation, thicker walled nutplates. This is significant because residual stress has been shown to be the best proxy for fatigue life, providing further evidence that the thin walled nutplate disclosed herein will produce similar fatigue life benefits as thick walled nutplates without the edge distance limitations. Residual stress typically starts 1 mm from the hole which does enable crack initiation, but provides a “wall” for further cracking starting at the 1 mm radius around the hole. That can be seen in the −20 to −37 KSI stress values at 1 mm distance from the edge of the hole. 
     Installation Tool  200   
       FIG. 10A  and  FIG. 10B  illustrate exploded and cutaway views of a representative embodiment of installation tool  200  of the present disclosure. Installation tool  200  may generally include a pull assembly  210  and a force measurement assembly  220  for installing and measuring applied installation forces, respectively. More specifically, pull assembly  210  may be configured for expanding bushing  120  of fastener  100  within hole  12  of structure  10 , and force measurement assembly  220  may be configured for measuring the pull force applied by pull assembly  210  to fastener  100  during installation. As configured, embodiments of installation tool  200  may provide for an easy and efficient, one-step installation process in which installation force is automatically measured during installation of fastener  100 . As later described in more detail, installation tool  200  may be configured to evaluate the measured installation force and provide immediate feedback to a technician as to whether the installation was successful, which can in turn reduce installation and maintenance times, and improve reliability and part lifespan, amongst other benefits. Further, installation tool  200  may record the installation force measurements for each fastener  100  that is installed, and thereby create an auditable record that may be analyzed to improve installation and maintenance protocols, and to reduce the need for supervision over the installation process, amongst other benefits. While installation tool  200  may be described in the context of installing fastener  100  throughout the present disclosure, it should be recognized that installation tool  200  may be used for installing any number of suitable fasteners, such as existing nut plates, on structure  10 , particularly those including a component(s) similar to bushing  120  that is configured to be inserted into and expanded within hole  12 . 
     Pull Assembly  210   
     Pull assembly  210 , in various embodiments, may generally comprise a tapered mandrel  211  and a drive mechanism  201  configured to retract mandrel  211  for expanding fastener  100  within hole  12 . In the representative embodiment shown, drive mechanism  201  may generally include a lead screw  212  and a threaded screw  213 . Generally speaking, lead screw  212  may be turned (e.g., by a impact driver) to drive threaded sleeve  213  for extending and retracting tapered mandrel  211  during the installation process, as later described in more detail. Installation tool  200 , in various embodiments, may further include a lead screw bearing  214 , a guide rod  215 , and mandrel guides  216 , all of which may be contained within a housing  217 , as described in more detail below. 
     Threaded sleeve  213  may be configured to travel along a longitudinal axis inside housing  217  during operation. Motion of threaded sleeve  213  may be initiated by turning lead screw  212  in the clockwise or counter-clockwise direction. In reference to  FIG. 10A , threaded sleeve  213  may be configured to travel in a first direction (e.g., towards a distal end of installation tool  12 , shown here as downwards) if lead screw  212  is turned in the clockwise direction and threaded sleeve  213  may be configured to travel in a second, opposing direction (e.g., towards a proximal end of installation tool  12 , shown here as upwards) if the lead screw  212  is turned in the counter-clockwise direction. Lead screw bearing  214  may be located in housing  217  with the purpose of positioning lead screw  212  in alignment with threaded sleeve  213 , and thereby providing a smooth rotation of lead screw  212 . 
     Threaded sleeve  213 , in various embodiments, may be located within housing  217  by guide rod  215 . Guide rod  215  may be stationary inside housing  217  such that it prevents threaded sleeve  213  from spinning about the longitudinal axis of installation tool  200  during operation. Motion of threaded sleeve  213  may be limited in a proximal direction by lead screw bearing  214  at the proximal end of installation tool  200 , and limited in a distal direction by first pressure plate  224   a.    
     Attached to a distal end of threaded sleeve  213  is mandrel  211 . Mandrel  211 , in various embodiments, may be attached to threaded sleeve  213  in such a way that it travels with threaded sleeve  213  in the distal and proximal directions during operation. In various embodiments, one or more mandrel guides  216  (three shown) may be provided in a distal section of installation tool  200 . Mandrel guides  216  may be configured to work together to allow mandrel  211  to enter and exit the distal end of installation tool  200  during operation. Housing  216  may include end caps  216   b,    216   c  configured for positioning on the distal and proximal ends of housing body  216   a,  respectively. End caps  216   b,    216   c  may be configured to contain the aforementioned internal components within housing body  216   a  and may be held in place by one or more retention bolts  216   d.    
     Force Measurement Assembly  220   
     Force measurement assembly  220 , in various embodiments, may generally comprise a force sensor  222  (e.g., a load cell) and a free-floating component  202 . In the representative embodiment shown, mandrel guides  216  serve as free-floating component  202 , though one of ordinary skill in the art will recognize other free-floating components suitable for functioning in the presently described manner without departing from the scope of the present disclosure. 
     Generally speaking, in various embodiments, force sensor  222  may be situated inside of housing  217  adjacent to free-floating component  202 , and free-floating component  202  (e.g., mandrel guides  216 ) may extend partially beyond the distal end of housing  217  (i.e., beyond cap  217   c ). As configured, when mandrel  211  is retracted into housing  217 , the force used to pull mandrel  211  will be transferred from pull assembly  210  to force measurement assembly  220 . In particular, during the installation process, the portion of mandrel guides  216  extending from the distal end of housing  217  contact structure  10  in which fastener  100  is being installed, and thus mandrel guides  216  assume the pressure generated between installation tool  200  and structure  10  when mandrel  211  is retracted by pull assembly  210  to expand bushing  210 . Mandrel guides  216 , in turn, transfer the applied pressure to the adjacent force sensor  222 . In an embodiment, load cell  211  may be configured to measure pressures between about 0 pounds to about 10,000 pounds and thereby accommodate a variety of installations. 
     Force measurement assembly  220 , in various embodiments, may further include one or more components  224  configured for uniformly distributing installation forces onto load cell  210 . In a representative embodiment, these optional components may include one or more pressure plates  224  positioned between load cell  210  and components of pull assembly  210 , so as to receive forces associated with the pull of mandrel  211  and distribute them evenly onto force sensor  222  in a perpendicular direction. For example, in the embodiment shown, first and second pressure plates  224   a,    224   b  may be positioned on opposing sides of force sensor  222 . More specifically, first pressure plate  224   a  may be situated between a proximal side of force sensor  222  and a flange extending inwards within housing body  217   a  as shown, and second pressure plate  224   b  may be situated between a distal side of force sensor  222  and free-floating component  202  (e.g., mandrel guides  216 ). As configured, mandrel guides  216  assume the pressure generated between installation tool  200  and structure  10  when mandrel  211  is retracted by pull assembly  210  to expand bushing  210 , and transfer the applied pressure to second pressure plate  224   b.  In turn, second pressure plate  224   b  distributes the transferred force to the distal side of force sensor  222 . First pressure plate  224   a,  as positioned against the proximal side of force sensor  222 , effectively acts a flat backstop against which second pressure plate  224   b  sandwiches force sensor  222 , and thereby works in concert with second pressure plate  224   b  to further help distribute the applied forces uniformly and perpendicularly against force sensor  222 . In various embodiments, mandrel guides  216 , pressure plates  224   a,    224   b,  and force sensor  222  may be free floating inside housing  217  and are retained in housing  217  by the bottom cap  217   c.  The term “free floating” refers to the fact that these parts are manufactured to have a smaller outer diameter than the inner diameter of housing body  217   a,  such that these parts may move as needed within housing  217  to provide a uniform and perpendicular force on force sensor  222 . 
     Referring now to  FIG. 11A , force sensor  222 , in various embodiments, may be connected to a digital read out device configured to record pressure measurements throughout the installation process. In an embodiment, a wired connection may be made by running a wire connecting force sensor  222  and the digital read out device through the side of housing body  217   a,  as directly to the digital read out device, as shown. In another embodiment, the digital readout is a screen embedded in the tool. 
     Referring now to  FIG. 11B  and  FIG. 11C , the digital readout device, in various embodiments, may record pressure measurements several times per second (e.g., at least 60 times per second) so as to accurately capture one or both of a maximum and total force applied by installation tool  200  to fastener  100  during installation. In an embodiment, the digital readout device may sample the applied force at a rate between about 50 Hz to about 999 Hz. From the pressure measurements recorded on the digital read out device, a pass/fail determination can be made in regards to the installation. For example, the digital readout device may be programmed with an acceptable range of forces within which the installation of fastener  100  is considered successful, and outside of which the installation is considered unsuccessful. Depending on the particular application and circumstances, the digital readout device may compare the maximum measured force against a range of maximum forces considered acceptable for a successful installation, and/or may compare the total force (i.e., (total area under the curve of all the force applied during installation, as shown in  FIG. 11D ) recorded by force sensor  222  throughout installation against a range of total forces considered acceptable for a successful installation. The criteria used in determining acceptable ranges of forces for a pass/fail determination may include, without limitation, one or a combination material characteristics of structure  10  (e.g., type, grade), the dimensions of structure  10  (in particular, thickness), and the size of fastener  100  (in particular, wall thickness  126  of bushing  120  thereof), amongst others. To that end, digital readout device may be provided selector buttons or another suitable interface that allows a technician using installation tool  200  to select these criteria, as shown in  FIG. 11B  and  FIG. 11C . For example, this interface may allow the technician to select material type of structure  10  (e.g., aluminum, steel, titanium, and grades thereof), thickness of structure  10  (e.g., 0.040, 0.060, 0.090, 0.100, 0.125, 0.188, 0.250), and diameter of fastener  100  (e.g., #6, #8, #10, ⅛, 3/16, ¼, 5/16, ⅜, 7/16, ½). 
     The digital readout device, in various embodiments, may automatically provide a visual, audible, tactile, or other form of notification to the technician using installation tool  200  as to whether the measured installation force fell within the acceptable range (i.e., pass/fail). For example, digital readout device may present a pass/fail message on its screen, or a light may illuminate (e.g., green for successful, red for failure) and/or blink (e.g., blink for successful, solid for failure) to indicated whether the installation passed or failed. Additionally or alternatively, the digital readout device may produce an audible notification indicative of pass/fail, such as a single beep for pass and multiple successive beeps for failure. Still further, the digital readout device may additionally or alternatively provide a tactile indication of pass fail, such as a short vibration for pass and multiple successive vibrations for failure. 
     Representative Installation Process 
       FIG. 12A ,  FIG. 12B ,  FIG. 12C ,  FIG. 12D ,  FIG. 12E ,  FIG. 12F , and  FIG. 12G  depict various steps of a representative process for installing fastener  100  with installation tool  200 .  FIG. 12A  displays the tool in its fully extended state, ready to begin the installation process. Next, as shown in  FIG. 12B , split sleeve  218  may be positioned over mandrel  211 . Split sleeve  218 , in an embodiment, may be manually attached to the outer diameter of mandrel  211  by sliding split sleeve  218  over the distal end of mandrel  211  and positioning split sleeve  218  so that a proximal end of split sleeve  218  is in contact with mandrel guides  216 . Referring now to  FIG. 12C , mandrel  211  (with split sleeve  218  thereon) may be inserted into hole  12  in structure  10 . Installation tool  200  may be positioned so that mandrel guides  216  are in contact with the surface of substrate  10  surrounding hole  12 . Next, as shown in  FIG. 12D , fastener  100  may be positioned in hole  12  such that inner surface  124  (not shown) is positioned about split sleeve  218  on mandrel  211 . More specifically, fastener  100 , in an embodiment, may be slid, bushing  120 -first, over mandrel  211  and split sleeve  218 , and towards hole  12  until bottom surface  112  (not shown) contacts the surface of structure  10  surrounding hole  12 , as shown. 
     Referring now to  FIG. 12E , a driving device (e.g., pneumatic, hydraulic, battery powered or manual), such as the impact driver shown, may be attached to the head of lead screw  212  at a proximal end of installation tool  200 . Of course, in some embodiments, installation tool  200  may further include an integrated drive device, such as an electric motor and any necessary gearing, for driving drive mechanism  201 . Next, as shown in  FIG. 12F , the driving device may then be activated to turn lead screw  212  in a clockwise or counter-clockwise direction. The clockwise rotation of lead screw  212  pulls threaded sleeve  213  towards the proximal end of installation tool  200 , causing mandrel  211  to be retracted into housing  217 . Mandrel  211  may be threaded into the distal end of threaded sleeve  213  and therefore travels the same distance and direction as threaded sleeve  213 . During this installation step, split sleeve  218 , fastener  100 , and structure  10  remain stationary and mandrel guide  216  remains in contact with structure  10 . As threaded sleeve  213  travels in the proximal direction and mandrel  211  retracts into housing  217 , split sleeve  218  positioned about mandrel  211  contacts mandrel guides  216  and is held in a stationary position until mandrel  211  has fully retracted into housing  217 . Retraction of tapered mandrel causes bushing  120  of fastener  100  to expand within hole  12 , thereby coldworking hole  12  and creating a friction fit between bushing  120  and hole  12  or an enhanced bond via adhesive  130 , as previously described. After the driving device has turned lead screw  212  until threaded sleeve  213  makes contact with lead screw bearing  214 , the driving device is deactivated. Referring now to  FIG. 12G , with fastener  100  securely installed within hole  12 , mandrel  211  may be fully retracted into housing  217 , and split sleeve  218  can be manually removed from inside fastener  100 . 
     Force Measurement Adapter  300  for Existing Pullers 
       FIG. 13A  and  FIG. 13B  illustrate perspective and cutaway views of a representative embodiment of a force measurement tool  300  for measuring a force associated with installing fastener  100  and/or expanding hole  12  (e.g., during a coldworking process). Unlike installation tool  200  which includes components for both pulling a mandrel and measuring installation and/or coldworking forces, force measurement tool  300 , in various embodiments, may be configured to be installed on and measure such forces generated by existing pullers. Accordingly, installation tool  300  may at times be referred to as “adapter  300 .” Adapter  300  may generally include an adapter assembly  310  configured for coupling with a puller  400 , and a force measurement assembly  320  similar to that of installation tool  200 . 
     Adapter assembly  310 , in various embodiments, may include an adapter  312  that is shaped and dimensioned for coupling with a nose or similar distal portion  410  of a traditional puller  400 , as later shown and described in more detail with respect to  FIG. 14A ,  FIG. 14B  and  FIG. 14C . Adapter assembly  310  may additionally include a mandrel adapter  314  which, in various embodiments, may replace the mandrel that may ordinarily be included with or attached to traditional mandrel  400 . In particular, mandrel adapter  314  may include a mandrel having a proximal end dimensioned and shaped for coupling with a mandrel receiver  414  of traditional puller  400 , as later shown and described in more detail with respect to  FIG. 14A ,  FIG. 14B  and  FIG. 14C . These components of adapter assembly  310  combine with puller  400  to pull mandrel  314  through hole  12  to coldwork the hole and/or expand fastener  100 , similar to pull assembly  210  of installation tool  200 . 
     Force measurement assembly  320 , in various embodiments, may include a force sensor  322  and a free-floating component  302  as shown in  FIG. 13B . These components may be positioned and arranged to function similar to force sensor  222  and free floating component  202  of installation tool  200 . That is, when adapter  300  is installed on puller  400 , and puller  400  operated to pull the mandrel, free-floating component  302  applies an axial force against force sensor  322  and thereby measures the associated force of the installation and/or coldworking operation. While not shown, force measurement assembly  320  of adapter  300 , in some embodiments, may further include [plates] similar to those of force measurement assembly  220 . 
     It should be appreciated that the description of various components of force measurement assembly  220  of installation tool  200 , and their corresponding arrangements and functionalities, are hereby incorporated and adapted for use in force measurement assembly  320 . Further, adapter  300  may be connected to a digital read out device configured to record pressure measurements throughout the installation process, similar to that described in association with installation tool  200 . 
       FIG. 14A ,  FIG. 14B  and  FIG. 14C  illustrate schematic views of adapter  300  configured for use with various existing pullers  400 . For example,  FIG. 14A  illustrates a housing adapter  300  configured for installation on a Fatigue Technology (FTI) puller gun. Adapter assembly  310  may be positioned and secured to a nose  410  of the FTI puller gun  400 . In particular, mandrel adapter  314  may be externally threaded such that it may be screwed into an internally threaded mandrel receiver  414  of the FTI puller gun  400 , and housing adapter  312  may be dimensioned for a friction fit on nose  410  of the FTI puller gun  400 . As configured, when the FTI puller gun  400  is activated, the mandrel of adapter  300  is pulled through the hole and/or fastener and force measurement assembly  320  measures the associated force. 
     As another example,  FIG. 14B  illustrates an adapter  300  configured for installation on a West Coast Industries (WCI) puller gun. Adapter assembly  310  may be positioned and secured to a nose of the WCI puller gun  400 . In particular, mandrel adapter  314  may be externally threaded such that it may be screwed into an internally threaded mandrel receiver  414  of the WCI puller gun  400 , and housing adapter  312  may be internally threaded such that it may be screwed onto external threads  412  on the nose of the WCI puller gun. As configured, when the WCI puller gun  400  is activated, the mandrel of adapter  300  is pulled through the hole and/or fastener and force measurement assembly  320  measures the associated force. 
     In yet another example,  FIG. 14C  illustrates an adapter  300  configured for installation on a Fastening Systems International (FSI) puller gun. Adapter assembly  310  may be positioned and secured to a sleeve  410  of the FSI puller gun  400 . In particular, mandrel adapter  314  may be externally threaded such that it may be screwed into an internally threaded extended straight pulling head  414  of the FSI puller gun  400 , and housing adapter  312  may be internally threaded such that it may be screwed onto external threads  412  of an adjustable adapter shaft of the FSI puller gun. As configured, when the FSII puller gun  400  is activated, the mandrel of adapter  300  is pulled through the hole and/or fastener and force measurement assembly  320  measures the associated force. 
     Tracking Pull Force Measurements Across Structure  10   
     Installation tool  200  and adapter  300 , in various embodiments, may be configured for associating pull force measurements with the location of each corresponding fastener  100  installed in structure  10 . As configured, installation tool  200  and adapter  300  may provide an auditable record of pull forces imparted to the various fasteners  100  in a given structure  10 . 
     In particular, by associating each pull force with the location of each corresponding fastener, installation tool  200  and adapter  300  may provide for identifying specific fasteners  100  that may require further action. For example, consider a situation in which fasteners were considered successfully installed within a given range of forces, but after future inspection it was determined that the upper end of the range was too high, as many of the fasteners exhibited bushing  120  damage and subsequently fell out. In such a situation, it may be beneficial to identify which remaining fasteners  100  were installed at forces above that threshold where damage occurred, so that such remaining fasteners could be repaired or replaced. 
     Additionally or alternatively, by associating each pull force with the location of each corresponding fastener, installation tool  200  and adapter  300  may provide for determining adjustments for future installations. For example, consider a structure  10  in certain fasteners  100  or associated holes  12  seemed to exhibit problems (e.g., fasteners torqueing out, or higher than normal cracks/corrosion around hole). In such a situation, maintenance personnel may be able to analyze the auditable record of pull forces provided by installation tool  200  to identify the portions of structure  10  (and similar structure on the same vehicle or other vehicles in a fleet) affected by the issue (whether it be due to increased loads on structure  10  in that location or something else), and revise the range of acceptable pull forces at those locations for immediate maintenance or future installations on similar vehicles in the fleet. 
     To that end, with reference now to  FIG. 15A ,  FIG. 15B , and  FIG. 15C , installation tool  200  and adapter  300 , in various embodiments, may be provided with a radio frequency identification (RFID) reader, barcode reader, or similar device  510  configured to scan an RFID tag, barcode, or similar identifier  520  associated with each fastener  100 , structure  10 , and/or hole  12 , depending on the particular embodiment. For the sake of simplicity, and without intending to limit the present disclosure, these embodiments will be described in the context of RFID technology only, with installation tool  200  including an RFID reader  510  and each fastener  100 , structure  10 , and/or hole  12  including a passive RFID tag  520 . In a representative embodiment, each fastener  100  may be provided with a unique RFID tag  520  that is scanned by the RFID reader  510  on adapter  300  ( FIG. 15B ) or installation tool  200  ( FIG. 15C ) at the time each particular fastener is installed. To improve the efficiency of installation, and/or to avoid accidentally forgetting to scan the RFID tag  520  on one or more fasteners  100 , the RFID reader  510  may be configured to scan the RFID tag  520  during the installation of each fastener  100 . For example, installation tool  200  and adapter  300  may be programmed such that powering the drive device to pull mandrel  211  also serves to automatically activate RFID reader  510  at the same time. As configured, the RFID reader  510  of installation tool  200  would be positioned close to the RFID tag  520  of the particular fastener  100  being installed, and thus could read the identification of that particular RFID tag  520  while not reading the identifications stored on the RFID tag  520  of fasteners installed nearby or awaiting installation (e.g., in a bin carried by the technician). To that end, in an embodiment, RFID reader  510  may be positioned near the distal end of installation tool  200  or adapter  300 , as shown, so as to minimize a distance during the installation process between the RFID reader  510  and the RFID tag  520  of a fastener  100  being installed. The RFID tag  520  could be situated in any suitable location on fastener  100 , and in an embodiment, may be implanted in a cavity on the face of fastener  100 . 
     The RFID reader  510 , in an embodiment, may have a wired connection to the digital readout device or other electronic system storing pull force measurements and associated locations (e.g., a computer, paired mobile device, etc.), while in another embodiment, RFID reader  510  may be in wireless communication with such systems (e.g., via Bluetooth, Zigbee or other wireless protocols). In addition or alternative to remotely storing pull forces, pass/fail indications, and other relevant parameters for each installation, installation tool  200  or adapter  300 , in an embodiment, may be configured to write the measured pull force and associated information to the RFID tag  520  on the corresponding fastener  100 . 
     Similarly, with reference now to  FIG. 16A  and  FIG. 16B , installation tool  200  or adapter  300 , in an embodiment, may be equipped with a device  600  for automatically marking structure  10  near fastener  100  (or fastener  100  itself) with at least an indication of whether the installation passed or failed. For example, installation tool  200  or adapter  300  may include a spraying device  600  near its distal end that is configured to automatically spray a green dot or a red dot nearby hole  12  if the installation passed or failed, respectively. While spraying device  600  is shown as an external attachment, it should be recognized that spray device  600  may be integrated internally within installation tool  200  or adapter  300 . Further, an extendible ink pen or other such marking device may be substituted for spraying device  600  in various embodiments. In the event an installation failed, the technician could come back to those fasteners marked with red dots and repair/replace each if warranted by visual or other inspection. Additionally or alternatively, the technician could leave the failed fastener installation(s) as-is, and maintenance personnel could pay particular attention to fasteners  100  marked with red dots when performing structural inspections. 
     As configured with RFID reader  510  and RFID tags  520 , engineers could analyze the associated auditable record of pull forces, and technicians could locate those fasteners needing repair, replacement, or inspection by scanning the RFID tags  520  of installed fasteners  100  in structure  10 . In various embodiments, structure  10  may additionally or alternatively be provided with an RFID tag  520 , such that a technician may more easily locate the particular structure containing specific fasteners  100 . In an embodiment, technicians could follow a particular path and order for installing fasteners  100  (e.g., defining a consistent starting point and working away from there in a consistent pattern), and thereby facilitate efforts to locate specific fasteners  100  requiring maintenance on structure  10 . 
     Additionally or alternatively, installation tool  200  or adapter  300 , in various embodiments, may be configured to track the exact location of each fastener  100  installed in structure  10  may be tracked and store it with the associated pull force. In one such embodiment, a projection system may be used to project light beams to indicate where holes  12  should be drilled on structure  10  during a new build. In particular, the projection system may utilize a  3 D model of structure  10  and desired hole  12  locations (e.g., CAD model, or model of the structure  12  itself created via a 3-D scan) create a projection pattern configured to aim a separate light beam onto structure  10  itself at that various locations in which holes  12  are to be drilled and fasteners  100  installed. Each light beam could have different properties (e.g., color, wavelength) for indicating the type and size of fastener  100  to be installed at each respective location. A display associated with the projection system may provide instructions to the technician, and track the location of installation tool  200  or adapter  300  throughout the installation process. Installation tool  200  or adapter  300  could even be equipped with an optical sensor configured to automatically scan the properties of the light beam being projected onto a corresponding location on structure  10  during installation of a fastener  100  at that location, and thereby associate the measured pull force with the location associated with that particular light beam. In another such embodiment, the installation tool can be integrated through an Augmented Reality Projection System such as Delta Sigma Corp&#39;s ProjectionWorks™ via a set of plugin tasks to utilize their Zigbee wireless communication link to guide data collection from the tool and to assess the quality of the installed nutplates. The resulting data will be recorded in a database, and ProjectionWorks can be then be used to project the results directly on the part in work. 
     In addition or alternative to associating pull force with the location of each fastener  100 , in various embodiments installation tool  200  or adapter  300  may be configured to warn or prevent a technician from performing an incorrect or otherwise undesirable installation. For example, if installation tool  200  or adapter  300  is in the wrong location (e.g., near the wrong hole  12  in structure  10 ) or about to perform the wrong action (e.g., apply force outside of the appropriate range of forces for a successful install), software may be configured to sound a warning and/or prevent installation tool  200  or adapter  300  from functioning until it is in the correct location or configured to perform the proper action. 
     Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.