and B parts, when required for part assessment, design values appropriate to each identified influence 
factor shall be developed and incorporated into the MPS. 

6.7.3 Explicit 
Evaluation of 
Anisotropy 
[AMR-69] Each MPS for Class A and B parts shall explicitly include supporting data necessary to evaluate the effects of 
anisotropy present in the AM material produced to a QMP such that anisotropy is either properly incorporated into the materia l 
allowables and associated design values, or rationale for a bounding isotropic assumption is established. 

6.8 Criteria for the 
Use of External 
Data in the MPS 
[AMR-70] For Class A and B parts, material property data generated outside the jurisdiction of this NASA Technical Standard 
(e.g., prior industry or government data), shall meet each of the following criteria prior to incorporation into or establishment 
of an MPS: 
a. Properties are generated from material produced by a documented AM process fundamentally the same as those 
already registered to the MPS. 
b. Authenticating records of traceability are available for the feedstock chemistry and post -AM operations (e.g., heat 
treatment). 


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
c. Properties are generated from material tested in a material condition (e.g., heat treatment and microstructure) 
equivalent to that defined by QMPs registered to the MPS. 
d. Authenticating records of traceability are available that illustrate the material internal quality and final microstructure.  
e. The size, geometry, build orientation, and surface condition of test specimens are defined. 
f. The specifications governing the material test methods are defined. 
g. The external data are provided in the form of actual test results to allow material allowables and PCRD criteria to be 
established or independently verified. 
h. Demonstration that active QMP(s) produce(s) materials equivalent in structure and mechanical properties, based on 
the registration process in section 5.6 of this NASA Technical Standard. 
6.9 Process Control 
Reference 
Distribution 
(PCRD) 
[AMR-71] For Class A and B parts, a PCRD shall be established as part of the MPS for each material property identified in 
Tables 5 and 6 requiring a PCRD for witness specimen test acceptance. 

6.10 PCRD 
Maintenance 
[AMR-72] For Class A and B parts, PCRDs specific to each MPS shall be reevaluated regularly following the incorporation of 
new witness data and updated as required. 

6.11 Development of 
Material 
Allowables and 
Design Values 
[AMR-73] For Class A and B parts, material allowables and design values specific to each AM material and condition shall be 
developed or otherwise substantiated according to the requirements and guidance of section 6.11 of this NASA Technical 
Standard for all applicable properties and environments required for structural assessment.  

6.11.1 Configuration 
Control of 
Material 
Allowables and 
Design Values 
[AMR-74] For Class A and B parts, material allowables and design values shall be maintained under configuration control as 
an integral part of an MPS. 

6.11.2 Design Values 
Development 
[AMR-75] For Class A and B parts, design values established to incorporate the effects of influence factors shall be developed 
on the AM material and have a statistical significance equivalent to the respective type of material allowable.  

6.11.3 Minimum 
Variability 
Requirements for 
Strength-Related 
Material 
Allowables 
[AMR-76] Statistical assessment of material data for strength-related material allowables shall incorporate a minimum CoV 
according to Table 21, Required Minimum Coefficient of Variation in Metallic Strength Material Allowables, unless the data 
set specifically includes data representing variability attributable to differences between specimen and part performance, in 
addition to all other specified requirements for variability in section 6.5 of this NASA Technical Standard.  

Table 21—Required Minimum Coefficient of Variation in Metallic Strength Material Allowables 
Quantity of Specimens Required Minimum CoV, 
Metals 
Required Minimum CoV, 
Polymers 


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
≤30 5% 7% 
31 to 60 4.5% 6.5% 
61 to 99 4% 6% 
100 to 299 3.5% 5% 
≥300 3% 4% 

6.11.4.2 Material 
Allowables for 
Tension 
Properties 
[AMR-77] For Class A and B parts, statistical assessment of metallic AM material test data to derive material allowables for 
ultimate strength, yield strength, and elongation shall be governed by the following: 
a. Test specimens are machined to represent bulk AM material and are tested according to ASTM E8/E8M or an 
equivalent standard.  
b. Material allowables are bounded by the 99% probability at a 95% confidence one-sided tolerance limit estimated for 
the population using a properly fit statistical distribution.  
c. A minimum of 100 specimens, distributed according to the lot requirements found in section 6.5 of this NASA 
Technical Standard, are required to initially establish material allowables. 
d. Material allowables incorporate the minimum CoV requirements of section 6.11.3 of this NASA Technical Standard.  
e. The tensile property database is maintained by the CEO and updated on a periodic basis as additional data become 
available from process control-related activities, including witness sampling, preproduction article evaluations, QMP 
development, and machine qualification. 
f. Data analysis methodologies, except as noted in this requirement, follow the intent of the MMPDS guidelines for 
static tensile property development. 

6.11.4.3 Secondary 
Properties 
[AMR-78] For Class A and B parts, statistical assessment of the secondary properties of metallic AM materials to derive 
material allowables shall be governed by the following: 
a. Test specimens are machined to represent bulk AM material and are tested according to industry standard 
procedures. 
b. Material allowables are bounded by the 99% probability at 95% confidence one-sided tolerance limit estimated 
for the population using a properly fit statistical distribution.  
c. A minimum of 20 specimens, distributed according to the lot requirements found in section 6.5 of this NASA 
Technical Standard, are required to establish material allowables for secondary properties.  
d. Material allowables incorporate the minimum CoV requirements of section 6.11.3 of this NASA Technical 
Standard.  
e. The secondary property database is maintained by the CEO and considered for updating if there is a change in 
properties.  


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
f. Test and data analysis methodologies, except as noted in this requirement, should follow th e intent of the 
MMPDS guidelines. 
6.11.4.4 Fatigue Material 
Allowables 
[AMR-79] For Class A and B parts, as required for structural assessment or at customer discretion, the MPS for any AM 
material shall include material allowables for fatigue developed in accordance with the following policies: 
a. Fatigue initiation life properties are developed in the form of stress-life or strain-life curves through testing according 
to recognized industry standards (e.g., ASTM E466, Standard Practice for Conducting Force Controlled Constant 
Amplitude Axial Fatigue Tests of Metallic Materials, or ASTM E606/606M, Standard Test Method for Strain-
Controlled Fatigue Testing). 
b. Specimens are machined to represent the bulk AM material and meet the surface finish requirements of fatigue test 
standards. 
c. Ten or more tests are used to define a fatigue curve for a given condition and, for HCF, a minimum of four tests are 
within 10% of the stress defined as the fatigue limit (see the definition of fatigue li mit for this NASA Technical 
Standard). 
d. Fatigue properties are subject to the lot requirements of section 6.5 of this NASA Technical Standard.  
e. The process for developing material allowable fatigue curves from the test data is described in the documentation of 
MPS development per section 6.3 of this NASA Technical Standard. 
f. All fatigue curves are labeled with their basis (e.g., typical or bounding). 
g. If the MPS fatigue material allowables are applied to Class A and B parts with cycle counts ≥10 8, then fatigue test 
data are required to substantiate the fatigue curve in this regime, except for Class B parts, where a methodology for 
conservatively estimating such fatigue limits based on fatigue data at cycle counts <108 may be employed when 
properly documented. 

6.11.4.6 Fracture 
Mechanics 
[AMR-80] For Class A and B parts, when a design assessment includes evaluation of crack -like defects by fracture mechanics, 
the MPS shall include fracture toughness and fatigue crack growth-rate properties, in the worst-case material orientation, 
tested from AM material produced to an appropriate QMP, with lot requirements per section 6.5 of this NASA Technical 
Standard. 

6.11.4.7 Stress Rupture 
and Creep 
Deformation 
[AMR-81] For Class A and B parts, when required for part assessment, the MPS shall include material properties for stress 
rupture or creep mechanisms tested from AM material produced to an appropriate QMP, wit h lot requirements per section 6.5 
of this NASA Technical Standard. 

6.11.4.8 Joining 
(Welding/Brazing/ 
Soldering) 
[AMR-82] For Class A and B parts, material properties for joined AM components shall be developed through testing 
according to recognized industry standards (e.g., AWS B4.0) and incorporated into the applicable MPS with a statistical 
significance comparable to the base AM material properties using specimens from AM material manufactured from 
representative QMPs. 

6.11.5.1.2 Viscoelastic and 
Viscoplastic 
Response in 
[AMR-83] For Class B parts, loading rate dependence of mechanical properties, commensurate with application environments, 
shall be accounted for during material characterization and derivation of material allowables and design values.  


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
Mechanical 
Properties 
6.11.5.1.3 Notch Sensitivity [AMR-84] For Class B parts, materials with plastic tensile strain capability less than 3% shall be evaluated for notch 
sensitivity, commensurate with the applicable design criteria and structural assessment methods.  

6.11.5.1.4 Determination or 
Knowledge of Tg 
for Design 
[AMR-85] Class B parts shall not be used in environments with an operational range that causes the part to pass through its 
glass transition temperature (Tg), measured in accordance with ASTM D7028, Standard Test Method for Glass Transition 
Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA), or equivalent, unless 
otherwise substantiated as part of the integrated structural integrity rationale in the PPP (see section 7.3 of this NASA 
Technical Standard). 

6.11.5.1.5 Conditioning of 
Specimens for 
Moisture Content 
[AMR-86] For Class B parts, the moisture content of all polymeric test materials shall be known and controlled during 
property characterization to within a user-defined predetermined range. 

6.11.5.1.6 Use of Filled or 
Reinforced 
Polymer Materials 
[AMR-87] For Class B parts, structural reinforcement added to AM polymer materials shall be of nominally random 
orientation. 

6.11.5.2.1 Temperature and 
Environmental 
Effects 
[AMR-88] For Class B parts, as required for part assessment, the MPS shall include the effect of temperature, moisture, and 
other environmental effects on material properties based on testing of the AM product form.  

6.11.5.2.2 Chemical 
Compatibility 
[AMR-89] For Class B parts, compatibility of the polymeric AM material with any chemicals with a known potential for 
exposure to the AM material during manufacture or in service shall be evaluated for any detrimental influence on material 
performance. 

6.11.5.3 Physical and 
Constitutive 
Properties 
[AMR-90] For Class B parts, all physical and constitutive properties required for proper design assessment shall be evaluated 
on representative AM polymeric materials.  

6.11.5.4 Material 
Allowables for 
Tension and 
Compression 
Properties 
[AMR-91] For Class B parts, derivation of static strength material allowables in tension and compression shall be governed by 
the following: 
a. Test specimens are machined to represent bulk AM material and are tested according to appropriate polymer material 
test standards. 
b. Material allowables are bounded by the 99% probability at 95% confidence one-sided tolerance limit estimated for 
the population, using a properly fit statistical distribution. 
c. A minimum of 100 specimens, distributed according to the lot requirements in section 6.5 of this NASA Technical 
Standard, are required to initially establish material allowables. 
d. Material allowables incorporate the minimum CoV requirements of section 6.11.3 of this NASA Technical Standard. 


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
e. The property database is maintained by the CEO and updated on a periodic basis as additional data become available 
from process control-related activities, including witness sampling, preproduction article evaluations, QMP 
development, and machine qualification. 
f. Test and data analysis methodologies, except as noted in this requirement, follow the intent of the CMH -17 
guidelines for static tensile property development. 
6.11.5.5 Shear Properties [AMR-92] For Class B parts, material allowables for shear strength shall be explicitly characterized, as required for structural 
assessment, according to the following: 
a. Test specimens are machined to represent bulk AM material and are tested according to appropriate polymer material 
test standards. 
b. Material allowables are bounded by the 99% probability at 95% confidence one-sided tolerance limit estimated for 
the population, using a properly fit statistical distribution.  
c. A minimum of 20 specimens, distributed according to the lot requirements found in section 6.5 of this  NASA 
Technical Standard, is required to initially establish material allowables. 
d. Material allowables incorporate the minimum CoV requirements of section 6.11.3 of this NASA Technical Standard.  
e. The property database is maintained by the CEO and updated on a periodic basis as additional data become available. 
f. Test and data analysis methodologies, except as noted in this requirement, follow the intent of the CMH -17 
guidelines for static tensile property development. 

6.11.5.6 Flexural 
Properties 
[AMR-93] For Class B parts manufactured using material with plastic tensile strain capability less than 3%, the flexural 
strength shall be evaluated, if required, for the following scenarios: 
a. If used in structural assessment, providing confirmation of design criteria and structural assessment methods. 
b. If used as a process control indicator, providing criteria for process qualification and production process monitoring.  

6.11.5.7 Fatigue Material 
Allowables and 
Design Values 
[AMR-94] For Class B parts, when required for structural assessment or by the customer, the MPS for AM polymer materials 
shall include material allowables and/or design values for fatigue developed in accordance with the intent of the requirements 
in sections 6.11.4.4 and 6.11.4.5 of this NASA Technical Standard, with appropriate accommodations for polymeric material 
test standards and test methods. 

6.11.5.9 Sustained Load 
Creep 
Deformation and 
Stress Cracking 
[AMR-95] For Class B parts, if applicable to part design and required for structural assessment, the material response under 
sustained load conditions leading to creep mechanisms, crazing, or stress cracking shall be evaluated from AM material 
produced to an appropriate QMP, with lot requirements per section 6.5 of this NASA Technical Standard. 

6.11.5.10 Joining [AMR-96] For Class B parts, material properties for joining polymer AM products shall be developed to a statistical 
significance comparable to the base AM material properties using AM product manufactured from the same QMPs and 
incorporated into the applicable MPS. 

7. Part Production 
Plan (PPP) 
[AMR-97] A PPP for each AM part shall be developed by the CEO to address all requirements of this section, subject to 
review and approval by NASA. 


Section Description Requirement in this Standard 
Applicable 
(Enter Yes 
or No) 

Comments 
7.1 Part-Specific 
Information 
[AMR-98] For Class A and Class B parts, the PPP shall list the following minimum general information, or may reference 
other configuration-controlled documentation that is available to NASA on request: 
a. Drawing number and part name. 
b. Illustrations and/or CAD model views (with scale). 
c. The purpose of the part in context to the system. 
d. The operational environments (e.g., temperatures, fluids, radiation, etc.). 
e. Referenced build file name contained in the digital thread. 
f. Material (including material specifications, if applicable). 
(1)  Feedstock material specification. 
(2)  Part material specification (or equivalent). 
g. Identification of the QMP specified for production. 
h. Identification of a specific MPS for the associated material used for part assessment, including influence factors, if 
applicable. 
i. Serialization, part marking, and methodology for tracking individual parts, if applicable.  
j. Cleanliness, if special considerations or requirements apply (e.g., oxygen service, optical surfaces, delicate electronics, 
etc.). 
k. Qualification plan, when applicable. 

7.2 Part