powder when all heats 
independently meet the powder specification. 

Process Control Reference Distribution (PCRD):  A statistical model representing the 
nominal performance of a material property used for monitoring process control. A PCRD is 
developed for material produced to an approved QMP and tested with a consistent specimen 
geometry, size, orientation, and test procedure. A PCRD is used to define the acceptance criteria 
applied to selected witness tests for an AM build cycle; the data used to develop the statistical 
PCRD model are typically the result of nominal witness tests and other data generated with the 
same consistent specimen geometry and test procedure. 


Production Engineering Record:  A revision-controlled document or electronic record 
that defines and records the sequence of all major operations and their outcomes when producing 
a part. 

Protoflight:  The protoflight unit is intended for flight on which a partial or complete 
protoflight qualification test campaign is performed before flight (as opposed to an acceptance 
test campaign). See also NPR 8705.4, Risk Classification for NASA Payloads. 

Quality Management System:  A formalized enterprise-wide system of controls used to 
consistently realize processes and products that meet requirements, generate evidence of process 
and product conformance, preserve the integrity of conforming product through delivery to the 
customer, and provide for design and process corrections and improvements. 

Qualified Material Process (QMP):  The foundational AM process control of feedstock, 
machine process controls, and post-processes that enable parts to be built with a consistent 
process of verified material quality. The use of a QMP provides the rationale for the assumed 
material capability of a part and provides quantifiable metrics to monitor the quality of the 
material process over time. 

Qualified Material Process, Subsequent (Sub-QMP):  A qualified material process that 
has the same feedstock specification and controls, AM build processes (e.g., the same key 
process variables), and post-processing as an existing QMP. The commonality to the existing 
process allows for reduced testing to establish a qualified process. 

Qualified Part Process (QPP):  The full content of the candidate part process following 
completion of the AMRR process and approval by the CEO. The entirety of the QPP content is 
configuration controlled by the QMS such that any changes to the contents of the QPP require 
adjudication as defined in the AMCP. (See section 8.4 of this NASA Technical Standard. 

Reference Part:  A part, typically small, that pushes the limits of an AM process and is 
used to provide feedback on the rendering capability and quality of an AM build. 

Repair:  An action performed on a nonconforming part to make it acceptable for the 
intended use, but changes the material condition and/or results in the part not meeting all 
requirements, requiring a waiver or similar. 

Rework:  An action performed on a nonconforming part to meet all requirements and 
make it acceptable for the intended use. Rework may still require formal approval. 

Safety Hazard:  A condition, event, operation, process, equipment, or system that could 
cause or lead to severe injury, major damage, or mission failure if performed or built improperly 
or allowed to remain uncorrected. (See NPR 8715.3D, NASA General Safety Program 
Requirements.) 


Self-supporting Structure (unsupported limit):  Part features that may be built in an 
overhanging condition without the need for support structure below it. The maximum angle at 
which overhanging part features may be reliably built without supporting structure is the 
unsupported limit. 

Steady State:  A condition where variables that define the behavior of the system or the 
process are unchanging over time. 

Structure:  All components and assemblies designed to sustain loads or pressures, provide 
stiffness and stability, or provide support or containment. 

Structure, Primary:  That part of a flight vehicle or element that sustains the significant 
applied loads and provides main load paths for distributing reactions to applied loads. Also, the 
main structure that is required to sustain the significant applied loads, including pressure and 
thermal loads, and upon failure creates a catastrophic hazard. If a component is in an 
environment where no serious threat is imposed if it breaks, then it is not primary structure. 

Support Structure:  Supplementary, sacrificial material built along with a part used to 
anchor overhanging geometry, provide dimensional stability, and/or promote proper thermal 
management during an AM build. 

Surface Treatment:  A broad range of industrial processes that alter the surface of a 
manufactured item to achieve a certain property. 

T99:  Designation for the lower tolerance bound of a statistical distribution fit to material 
property data indicating at least 99 percent (%) of the population equals or exceeds this value 
with a confidence of 95%. See the MMPDS for further information. 

Trace Width:  The width of material produced during a single vector of the build process 
that is determined by key process inputs (e.g., energy source power, wire diameter, and/or 
filament diameter). 

Typical Basis:  An average value with no statistical assurance associated with it. 

Unique Build/Heat Treat Lots (material property lot requirements):  Material that does 
not have either build or heat treat lot commonality. 

Witness Line:  A visual demarcation along build layer planes indicating a change in 
steady-state operation of the AM process. The demarcation may be a geometry shift, a change in 
surface texture or coloration, or any other distinct nonuniformity. 

Witness Testing:  Tests conducted on a specimen built during the same build cycle as a 
part. These specimens will be used for SPC, process development, and building mechanical test 
databases. 


 GENERAL REQUIREMENTS 

4.1 Tailoring of this NASA Technical Standard’s Requirements 

[AMR-1] Program and/or project managers shall formally document and approve all tailoring 
of requirements in this NASA Technical Standard with the concurrence of the responsible NASA 
Materials and Processes (M&P) organization and the delegated Technical Authority in 
accordance with NPR 7120.5, NASA Space Flight Program and Project Management 
Requirements, or NPR 7120.8, NASA Research and Technology Program and Project 
Management Requirements. 

Tailoring may occur at two stages:  (1) prior to being levied, where the program or project 
tailors the requirements to suit its needs, and (2) prior to implementation, where the CEO tailors 
the as-levied requirements to provide a customized approach to implementation that meets the 
intent of the requirements. The following are the expected roles and responsibilities during the 
tailoring process. The program or project (i.e., entity responsible for defining the mission 
objectives, levying design and construction standards, accepting risks, and controlling cost and 
schedule resources) has an obligation to define and document any project-specific tailoring of 
these requirements prior to levying them. The responsible NASA M&P organization and the 
delegated Technical Authority have an obligation to review and concur (or not) with the 
intended project-specific tailoring and identify and assess any associated risks. Once levied, the 
requirements may be further tailored for implementation by the CEO through the AMCP. 
Tailoring for implementation proposed by the CEO is approved through formal acceptance of 
the AMCP by the responsible program or project, with the responsible NASA M&P organization 
and delegated Technical Authority providing concurrence (or not) along with identification and 
assessment of associated risks. 

4.2 Additive Manufacturing Control Plan (AMCP) 

[AMR-2] The CEO responsible for the design, acquisition, and conformance of AM hardware 
shall submit a consolidated AMCP addressing all applicable AM processes for review and 
approval by the responsible NASA program or project, with concurrence from the responsible 
NASA M&P organization, that does the following: 


a. Documents the means of conformance and method of implementation for each of the 
requirements of this NASA Technical Standard and NASA-STD-6033 (see section 4.5 of this 
NASA Technical Standard). 

b. Documents and provides rationale for any tailoring of the requirements of this NASA 
Technical Standard. 

c. Provides for complete governance for the implementation of AM on the program or 
project such that, once approved, the AMCP becomes the controlling document for 
implementation and verification of AM requirements of this NASA Technical Standard. 

[Rationale:  The AMCP is necessary to document the decisions made in the implementation of 
this NASA Technical Standard and becomes the governing document for the CEO regarding AM 
requirements.] 

Tailoring includes using existing or previously developed contractor processes and standards 
when identified and submitted as part of the AMCP. 

Projects that are only using Class C parts may choose to write a simple AMCP. Such an AMCP 
may only directly respond to requirements that apply to Class C parts. Most of the requirements 
for the QMP, MPS, qualification, and witness testing do not apply or are greatly reduced. 
While the AMCP is intended to be part agnostic, projects that are using a small number of 
similar or related Class C parts could choose to combine an AMCP with the limited PPP 
requirements given in section 7 of this NASA Technical Standard. 

Note:  The requirements of this NASA Technical Standard do not encompass all requirements for 
an AM part (e.g., fracture control). 

 Applicable Documents, AMCP 

[AMR-3] All applicable documents cited in the AMCP shall be controlled by the QMS, subject 
to configuration control, and made available for review when requested by NASA, the CEO, or 
any designated representatives. 

[Rationale:  Sufficient oversight of AM operations can only be conducted when NASA, the CEO, 
and any of their designated representatives has access to the controlling documents.] 

The majority of the technical details and controls necessary for the production of reliable AM 
parts will not typically be contained directly in the AMCP, but in documents cited as applicable 
in the AMCP. NASA, the CEO, or a designated representative will be provided access to these 
documents upon request. 


 Supplier Compliance with the AMCP 

[AMR-4] The CEO shall ensure flow-down of the requirements of this NASA Technical 
Standard, as tailored per the AMCP, through all relevant tiers of the supply chain and ensure that 
the relevant documents controlled by subtier suppliers are made available to NASA upon 
request. 

[Rationale:  The CEO is expected to rely on suppliers for aspects of producing AM parts. The 
quality of parts may be compromised at any stage of the process. This requirement precludes the 
use of suppliers whose products or services are not compliant with the controls of this NASA 
Technical Standard.] 

This supplier requirement is not limited to the AM part producer but extends to all potential 
suppliers and sub-tier suppliers involved in the process of designing and producing AM parts. 
For example, suppliers providing part processing or witness testing (e.g., heat treating, 
mechanical testing, or chemical analysis) are expected to be approved by the CEO and 
accredited through Nadcap™, the American Association for Laboratory Accreditation (A2LA), 
or other nationally accepted accreditation body.  

The CEO may require suppliers and sub-tier suppliers to develop a tailored plan to comply with 
this NASA Technical Standard or a tailored plan to comply with the CEO’s plan. Alternatively, 
the CEO may flow down a limited subset of (or even no) requirements, with the CEO making up 
the difference between the subset and the AMCP. Regardless of which approach is selected, the 
CEO is responsible for ensuring that hardware designed and fabricated by subcontractors 
and/or suppliers meets the approved AMCP or this NASA Technical Standard. 


4.3 Additive Manufacturing Part Classification 

 Primary Classification 

[AMR-5] The CEO shall assign a primary classification (i.e., Class A, B, or C) to all AM parts 
in accordance with the content of Figure 4. 

[Rationale:  Part classification is required to enable a consistent evaluation of part risk through 
defined metrics for consequence of failure, structural demand, and AM-associated risks.] 

See Figure 4 of this NASA Technical Standard for a graphical representation of the primary and 
secondary classification system. 

The classification system establishes a consistent methodology to define and communicate the 
risk associated with AM part designs. Throughout this NASA Technical Standard, these 
classifications determine appropriate levels of process control, qualification, and inspection. 

The part classification system uses a two-tier system to designate AM parts based on relative 
risk. The alphabetical class is determined by consequence of failure, with Class A being the 
highest and Class C being the lowest. An additional exempt designation is defined in section 
4.3.1.4 of this NASA Technical Standard. The numerical subclasses for Class A and B parts are 
determined by a combination of structural demand on the part and the risk associated with the 
AM implementation for the part. 


Figure 4—AM Part Classification 


 Class A Parts 

[AMR-6] A part shall be designated as Class A, High Consequence of Failure, if failure of the 
part leads to a catastrophic, critical, or safety hazard and/or the part is defined as mission critical 
by the program or project. 

[Rationale:  Parts with a high consequence of failure require more stringent controls on the AM 
process to manage risks associated with their use.] 

Note:  See Section 3.2 of this NASA Technical Standard for definitions of catastrophic, critical, 
and safety hazard, which are taken from NPR 8715.3D, NASA General Safety Program 
Requirements. Other NASA NPRs, NPDs, standards, specifications, and contracts may define 
these terms differently. In instances of conflict, the AMCP will need to clarify any deviations to 
the definitions provided herein. 

The consequence of failure for any human-rated hardware should be determined via FMEA or 
may follow from assessments done for fracture control classification. Considerations for high 
consequence of failure may also include the loss of mission objectives or the loss of a “national 
asset” or similar high-cost hardware or facility that warrants the added controls for Class A 
parts. Range safety requirements may also govern consequence of failure evaluations.  

4.3.1.1.1 Class A Part Restrictions 

[AMR-7] Class A parts shall not: 

 Be made from polymeric materials 
 Be fasteners. 
 Contain printed threads. 

[Rationale:  The current state of the art for AM is not yet mature enough for these categories of 
parts.] 

Non-metallic AM parts are intended for use only in Class B and Class C applications. 


 Class B Parts 

[AMR-8] Parts not designated Class A or Class C shall be designated as Class B.  

[Rationale:  Class B parts are not synonymous with benign failures—Class B parts are to be 
aerospace-quality parts of high reliability. Many failures falling short of catastrophic can 
produce major programmatic delays/impact. The consequence of failure for parts in non-flight 
development hardware should be based on collateral damage assessments and chosen at the 
discretion of the project. A higher class designation may always be chosen for a part.] 

4.3.1.2.1 Class B Part Restrictions 

[AMR-9] Class B parts shall not: 

 Be fasteners. 
 Contain printed threads. 

[Rationale:  The current state of the art for AM is not yet mature enough for these designs. 

Threads for Class B parts may still be machined or formed after AM printing. 


 Class C Parts 

[AMR-10]  A part shall be designated as Class C, Negligible Consequence of Failure, provided 
that ALL of the following criteria are satisfied: 

a. Failure of part does not lead to any form of hazardous condition. 

b. Failure of part does not eliminate a critical redundancy.  

c. Part does not serve as primary or secondary containment. 

d. Part does not serve as redundant structures for fail-safe criteria per NASA-STD-5019, 
Fracture Control Requirements for Spaceflight Hardware. 

e. Part is not designated “Non-Hazardous Leak Before Burst” per NASA-STD-5019. 

f. Failure of part does not cause debris or contamination concerns, as defined by the 
Non-Fracture Critical Low-Release Mass classification per NASA-STD-5019, NASA-STD-
6016, and/or other project/program requirements. 

Contamination requirements are commonly defined in interface control drawings. 

g. Failure of part causes only minor inconvenience to crew or operations. 

h. Failure of part does not alter structural margins or related evaluations on other 
hardware. 

i. Failure of part does not adversely affect other systems or operations. 

j. Failure of part does not affect minimum mission operations. 

[Rationale:  Class C designs have the lowest performance requirements and the fewest controls 
for realizing the performance specifications and process repeatability.]  

This class of parts allows tailored quality assurance and material performance controls due to 
negligible consequences of failure. Consideration of consequence have to include all possible 
end uses of the part, including protoflight scenarios or development hardware that may 
transition to actual flight hardware. 

For the above checklist, failure can be defined as any failure condition (including, but not 
limited to, yielding, buckling, cracking, fracture, leak, wear/galling, or corrosion) where the part 
does not achieve every aspect of its design intent. 


NASA-STD-6030 imposes a large number of process AMRs for Class A and Class B 
parts. Although Class C parts have a negligible consequence of failure, a minimum set of 
requirements is kept to ensure that flight parts still meet their intended function. A large number 
of AMRs are eliminated, and the remaining set of AMRs is selected to ensure that the AM 
process produces sound material. 

Many of the remaining AMRs were simplified to reduce cost, schedule, and complexity. The 
following are examples of simplified process controls for Class C parts: 

 For process qualification, only six tensile coupons are to be made and tested using the 
machine setup (see section 5.4