MIL-PRF-83261C
SAE AMS 6491
Steel Bars, Forgings, and Tubing 4.1CR 4.0MO 1.0V (0.80
0.85C) Premium Aircraft-Quality for Bearing Applications, Double
Vacuum Melted (M-50) (DoD Adopted)
(Copies of these documents are available online at https://www.sae.org or SAE International, 400
Commonwealth Drive, Warrendale PA 15096-0001 USA)
2.3. Order of precedence. In the event of a conflict between the text of this document and the
references cited herein (except for related specification sheets), the text of this document takes
precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a
specific exemption has been obtained.
3.
REQUIREMENTS
3.1 Toxicity. The materials shall have no adverse effect on the health of personnel when used
for their intended purpose.
3.2 First article. When specified (see 6.2), a sample shall be subjected to first article inspection
in accordance with 4.2.
3.3 Materials. The grease shall be a mixture consisting of a base fluid, a gelling agent and the
necessary additives. A formulation of a fluorinated polysiloxane fluid, a non-soap gelling agent, and the
necessary additives is recommended but is not mandatory.
3.4 Properties of finished fluid. The properties of the finished fluid shall be in accordance with
those listed in 3.4 and Table I.
3.4.1 Un-worked penetration. The un-worked penetration (as measured in units of 0.1 mm) of
the grease shall be a minimum of 280 when tested as specified in 4.4.3.
3.4.2 Worked penetration. The worked penetration (as measured in units of 0.1 mm) of the
grease shall be a minimum of 270 and a maximum of 350 when tested as specified in 4.4.3.
3.4.3 Workmanship. The grease shall be a high quality, smooth, homogenous product free from
abrasives and impurities when examined as specified in 4.4.2.
4.
VERIFICATION
4.1 Classification of inspections. The inspection requirements specified herein are classified as
follows:
a. First article inspection (see 4.2).
b. Quality conformance inspection (see 4.3).
4.2 First article inspection
4.2.1 First article samples. When required, a first article inspection shall be performed on a 5 kg
(12.5 pound) sample from a bulk lot (see 6.3) to determine conformance with section 3.
4.2.2 First article tests. First article sample(s) shall be subjected to all the tests specified in 4.4
and table II.
4.3 Quality conformance inspection. Quality conformance inspections shall consist of sampling
plans A and B. Samples shall be labeled completely with information which identifies the purpose of the
sample, name of the product, specification number, lot/batch number (see 6.3), date of sampling and
contract number.
4.3.1 Sampling plan A. A 5 kg (12.5 pound) sample from a bulk lot (see 6.3) shall be selected in
accordance with ASTM D4057 and subjected to inspection and tests specified in 4.4.1 and 4.4.2, and
3
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business