Al Standard Fasteners
The company IHF develops, produces and sells high- strength and high quality fastening elements in the form of bolts, nuts and washers. The product range consists of: - Strength Classes: 8.8, 10.9, 12.9, 13.9 -   Bolt Diameter: M12 – M64 -   Corrosion Protection: Dacromet, Deltaton, Galvanized
70,000 tons a year: One of the biggest producers of
bolts in Europe
IHF relies on the capacities and knowledge of its partner SBE. With more than 70,000 tons a year SBE is one of the biggest producers of bolts in Europe. The product range of IHF reaches from batch productions to various custom productions, like the HV-stretch-bolt for the wind power industry. IHF stands out with: ✔ Customer focus – Company procedures are focused on customer service ✔ High quality standards by steadily improving pro- duction reliability as a certified supplier ／ Complete traceability from the wire to the finished product ✔ Constant and controlled heat treatment of the product ／ In house nut production ✔ Innovative cold metal forming process JUMBOTECH™ ✔ Complete system supplier, engineering, tools, fastening elements, service
JUMBOTECH™ Production Process
The IHF-bolts are produced by the patented JUMBOTECH™ production process. This is the only cold metal forming process that allows for tight production tolerances of 0.05 mm on bolt sizes up to M69. In contrast to hot metal forming the JUMBOTECH™ process allows for the modern extrusion of the bolt directly from the drawn coil with a length of 150 to 200 metres. With cold metal forming you can eliminate the other expensive and time consuming manufacturing processes like sandblasting, machining and heat treating. All production steps are documented throughout the process. This makes complete traceability from the bolt to the basic material possible.
Engineering
The engineering department provides complete technical support to meet the customer requirements. This includes detailed assembly conditions, load measurements, and surface condition requirements. With this support the customer receives a technical solution with a commercial bolt connection.
Material Selection
The quality of the products begins with the selection of certificated suppliers. The materials used meet the re- quirements according to ISO 898-1 (bolts) and ISO 898-2 (nuts) regarding the chemical composition. Only carbon steel with additives or alloyed steel with suitable degrees of purity are used. Regarding surface defects the product class D according to DIN EN 10221 is used. The surface finish, chemical com- position, microstructure and formability are controlled in the lab. Special material requirements, such as thread forms and surface finishes can be supplied upon the customer's request.
Manufacturer Qualification
The production of the IHF-fastening elements is licensed and certified according to the following quality systems ISO 9001:200, ISO TS 16949:2002 and UNI EN ISO 14001 for the environment management system. The HV-sets fulfill the requirements of the German Building Rules List A, Part 1 and have compliance certificates, issued by an accepted corporation. Each product has a control plan and process run with detailed instructions for every step of manufacturing. In addition there are quality control plans with all valid quality processes and instructions. Documented control results are kept for 15 years. The quality certificates according to DIN 10204, torque certificates according to DIN 18800-7 and hydrogen certificates can be shown upon customer's request.
The Manufacturing Process
1.Wire rod stock yard Incoming wire coil is checked prior to acceptance on the basis of IHF's quality requirements and stored in specific areas to ensure error-free collection. 2. Wire coil heat treatment Computer controlled spheroid annealing is done in bell furnaces. 3.Wire rod pickling and phosphating A completely automated system renders the surface of the wire rod chemically homogeneous ready for the forging operation. This operation ensures uniform diameter of the wire coil. 5.Tool making Fundamental for a flexible manufacturing system, the tool making department is equipped with the machine tools needed to make the dies that are designed and drawn by our own Engineering Services department. 6. Tool heat treatment An important feature of the tool making process is vacuum heat treatment. 7. Thread rolling and tapping These recently updated and enlarged departments have facilities for threading every type of forging produced.
9. Toolstock
With an inventory of over 35,000 tooling components for forging equipment, IHF owns and manages an engineering heritage hard to equal.
8. Heat treatment
Continuous furnaces of different capacities (kg/h) with a controlled and constantly monitored atmosphere are used to achieve the mechanical strength properties specified for the various fasteners. 10. Packaging This department has been completely refurbished, and is capable of packaging all current production items automatically. 11. Forging It is at this stage of the process, using multi-station bolt makers and parts formers (cold forming up to 300 pcs/min), that parts are given their final shape.
Tightening procedure of preloaded Hv assemblies according to DIN 18800 part 7, 11/2008 Table 1 shows the preload and tightening torques for steel structural assemblies. The preload should be achieved by tightening the nuts. If the tightening is only possible by turning the bolt head it is necessary to use an approved and accepted tightening procedure with a suitable lubrication on the bearing face of the head of the bolt.The thread does not need further lubrication as this is already provided by the manufacturer through the built-in lubrication of the nut. The following procedures are available for applying preload, usually by turning the nut:
■ Torque procedure:
A torque M A taken from the table 1, column 3, shall be applied to achieve the specified preload Fy according to table 1, column 2. This procedure allows a gradual tightening when a joint has many bolts. Furthermore it is possible to inspect the bolts as well as to apply a second round of tightening after some days, to assure that the specified preload is achieved in each bolt;
■ Impact procedure
Nut is turned relative to the bolt by impact rotating through an air driven impact wrench.The wrench shall be set to preload Fv,וםaccording to column 4 of table 1 which is 10 % higher that that for the torque procedure;
■ Rotation angle procedure
To use this procedure all mating parts shall be flat and in a good firm contact with each other. After having achieved a pre-tightening torque M VA , DW according to column 5 of table 1, an additional rotation of the nut shall be applied to achieve the minimum specified preload indicated in table 1, column 2. The angle of nut rotation must be evaluated by an approved procedure on the original assembly.The elongation of the bolt under full preload might be a suitable measure;
■ Combined procedure
This procedure consists of two steps. Firstly a pre- tightening torque Mya, ky according to the table 1, column 6, has to be applied. After that, if the plates lie firmly together without any gap, a further angle of nut rotation according to table 2 shall be applied. Contact surfaces of the joints in preloaded bearing connections with normal HV bolts or with HV fit bolts should be treated as per DIN 18800 part 7.To prevent loss of preload it is necessary to tighten up all bolts in a further round. Retightening of fully preloading HV bolts after dismantling shall be avoided.The complete bolt assembly (bolt, nut and washers) must be replaced by a new one.
DIN 18800-7 includes diameters up to M36 – larger diameters M39, M42, M45, M48, M56, M64 can be produced according to DASt-Richtlinie 021 or customer specifications Application rules for connections with HV bolt assembly according to DIN 29900 part 1, 11/2008 and DIN 18800 part 7, 11/2008 Preloaded bolted assemblies are very sensitive to differences in manufacture and lubrication. Therefore, according to EN 14399-1 and DIN 18800-7, SBE bolts shall only be used together with SBE nuts and SBE washers. Please note that SBE HV nuts do not need additional lubrication. This could modify the original and approved torque-preloaded-relationship. Independently from the date of production,in case k-class K1  is required, SBE bolts, SBE nuts and SBE washers of the same diameter may be combined, but mixing bolts nut washers of different surface treatments is to be avoided. During the installation, the plain face of the washer with the marking should show to the joint. The face with the bevel should be shown to the bolt head or the nut. The nut face with the marking should be visible after assembly. In the preloaded connection the installed HV bolts must show a minimum one full thread protruding from the nut. To adjust the bolt length and the thread length with the thickness of the joint, packing up to washers or shims with 12 mm thickness maximum may be used on the side not turned. The parallelism of the two outside planes of the joint must be less or equal to 4 % (ca.2°) for steel constructions with no oscillating loads and if the assembly is tightened by the nut. In constructions under oscillating loads the parallelism must be less or equal to 2 % (ca. 1°), if the skewness is more than the values mentioned then cham¬ fered washers of sufficient hardness shall be applied. Bolted connections in U-profiles or in I-profiles of older size with sloped inside flanges need chamfered washers according DIN 6917 or DIN 6918. HV bolts tightened up to the specified preload need measures to prevent loosening of the preload. Short and long slotted holes possibly need enlarged washers or additional shims. They shall not be applied without the agreement of the design engineer. They are usually subjected to separate checks by the constructor. To calculate the torque, tension and the friction coeffi- cient of the assemblies, two test benches are available in the Laboratory, with a maximum torque of 18.000 Nm and a clamping load up to 1.800 kN.
Inspection of the specified preload of the bolt
assembly
Bolt assemblies shall be inspected to determine whether the inspected bolt is correctly tightened. Table 3 shows how to inspect the assemblies and measures to be taken on the basis of the inspection results. A minimum of 10 % of all HV bolts shall be inspected in steel constructions subjected to oscillating loads, while in steel constructions of buildings or industrial buildings it 's only 5 %. In joints with less than 20 HV bolts a minimum of 2 bolts shall be inspected. Before the inspection begins the position of the bolt, nut, washers and joint shall be marked on that side of the connection where the tightening has taken place. An inspection tool of the same type as the tightening tool shall be used as follows: adjustable hand tools and machine tools such as used in the torque control method shall be set to an inspection torque which is 10 % higher than it is listed in table 1, column 3; air driven impact wrenches shall be set to the preload listed in table 1, column 4. Tightening procedure must be revised and complete connections shall be checked again if tightening procedure parameters cannot be met. Table 2: Required additional angle of rotation σ and value of rotation V for the combined tightening method for 10.9 bolts
Table 3: Inspection of the specified bolt preload
a) In case of statically loaded bearing type connection with HV bolts or HV fit bolts without axial forces the inspected bolts may remain in the construction

Dimensions HV-Strenght hexagon head bolts,

Table 4: Dimensions of high-strength hexagon head bolts with large width across flats for structural steel bolting according to DIN 6914
8 
Inominal size 1)  P = pitch of thread (coarse thread) 2) For lengths above the continuous step line 3) For lengths below the continuous step line 4) The maximum value of d w shall not exceed the actual width across flats
EN 14399-6 washer EN 14399-8 HVP bolt
Flangethickness HV-Standard Fasteners
Table 5: Clamping lengths

Dimensions HV-Strenght hexagon head bolts,
UMBOTECH™ line

Table 6: Dimensions of high-strength hexagon head bolts with large width across flats for structural steel bolting M39 to M64
lg max. = Inominal size " 1)  P = pitch of thread (coarse thread) 2) The maximum value of d w shall not exceed the actual width across flats On customer request different diameters can be produced. nut Flangethickness HV-Standard, JUMBOTECH™ line
Table 7: Clamping lengths

elivery conditions EN 14399,
JUMBOT

Picture: JUMBOTECH™  Productionprocess, hexagon nut bolt M36
Total reliability and quality
■ High Quality System ■ Reliable and Qualified Suppliers ■ Traceability from raw material to the final product ■ Constant and Controlled heat treatment of the product ■ Complete Product Certification ■ Nut former manufacturing division ■ Supporting customers with new technical solutions SBE has developed an innovative production process JUMBOTECH™ that has moved the upper limit of cold forging for bolts to M64 mm, with a maximum weight up to 25 Kg and a manufacturing accuracy that allows us to keep a very narrow range of tolerances as little as 0,05 mm. Thanks to international patent JUMBOTECH™ – nº PCT/IT2003/000106 - we are even more competitive: contrary to the traditional hot forging process using six meter bars, SBE can start production directly from wire rod, with variations in length from 100 to 250 meters depending on the diameter. Secondly all the additional processes before thread rolling, such as shot blasting and machining can now be eliminated. With our German heat treatment supplier we have developed a bespoke continuous belt furnace with a capacity that covers the full range of the fasteners we forge with the new JUMBOTECH™ production process.
according to customer specification, Thread and Form tolerances according to customer sprecificatior standard IHF specification : Jose GmbH · Phone: +49 (0) 291 / 99 62 - 0 · Fax: +49 (0) 291 / 99 62 - 11 · sales@ihf-gmbh.com · www.ihf-gmbh.com   19 F A S T E N E R Ｓ Y Ｓ T E M S Applications HV-Fasteners-Set for wind turbine towers, according to EN 14399-, hot-dip galvanized. Stud-bolts M36 with hexagon nuts ISO 4032 and spacer for blade bearings on wind turbines, Xylan-Surface Protection. for blade bearings on wind turbines, with ITH-Round-Nut RMS and ITH-Bolt-Tensioning Cylinder.
Worldwide Service Facilities
IHF GMBH Auf’m Brinke 18 · D-59872 Meschede Phone: + 49 (0) 291 / 99 62 - 0 Fax +49(0)291/996211 liffie Europe IHF GmbH Phone: +49(0)291/9962-0 E-mail: sales@ihf-gmbh.com www.ihf-gmbh.com America ITH Eng. Company Inc., Chicago Phone: + (1) (847) 526 - 1980 E-mail: sales@itheng.com China ITH-GmbH Shanghai Rep. Office Phone: +86/1/64 82 35 80 E-mail: ith_sha@online.sh.cn South East Asia ITH Asia Pacific, Kuala Lumpur, Malaysia Phone: +60(3)/8061 - 6620 E-mail: sales.asia@ith.com Japan ITH Japan Co., Ltd, Funabashi City Phone: +81 / 47 - 493 - 5221 E-mail: sakai-ith@muse.ocn.ne.jp