MIL-DTL-197L
3.3.4.4 Shelf life. Bearing shelf life may be determined by the bearing lubricant or
preservative used during the bearing's packaging and by the type of packaging employed
(see table II). A detailed description of bearing shelf life requirements is beyond the scope of
this specification, however; the following may be used to guide determination of shelf life
requirements and actions for the described bearing types. Procuring activities should consult
manufacturer documentation for determination of bearing shelf life (see 6.2).
3.3.4.4.1 Closed race bearings. Closed race bearing shelf life may be determined by the
manufacturer's installation life (see 6.5.9) to arrive at an overall shelf life value. Typical
installation life will vary with the type of preservative or lubricant used and the type of
packaging. Procuring activities will consult with manufacturers to determine useable shelf life
3.3.4.4.2 Open race bearings. Open race bearings are cleaned and lubricated with their
operational lubricant prior to placement into service. Open race bearing shelf life may also be
extended by re-certification if suspected of having exceeded rated shelf life (see 3.12.4(b),
6.4.1.1, and appropriate end-user maintenance documentation - example: NAVAIR 01-1A-
503/U.S. Army TM55-1500-322-24/ USAF T.O. 44B-1-122, "Maintenance of Aeronautical
Antifriction Bearings for Organizational, Intermediate and Depot Maintenance Levels").
3.3.4.4.3 Self-aligning bearings. Self-aligning bearing shelf life shall be determined
using the same method as described in 3.3.4.4.1.
3.3.4.4.4 Self-lubricating bearings. Self-lubricating bearings require no additional
lubricant that might affect shelf life (see 3.12.4(e)). Procuring activities should consult the
manufacturer for determination of shelf life for self-lubricating bearings (see 6.2). Note that
sintered (powdered metallurgy) bearings are considered self-lubricating, but they are
impregnated with their operational lubricant and should be treated as self-aligning bearings.
3.3.4.5 Visual check. A visual check of all lubricants shall be made every 12 months on
all containers that have been opened. The visual inspection shall be conducted prior to use. The
containers that have been opened shall be checked for: proper color, all forms of visual
contamination, evidence of water, and evidence of separation. Any lubricants that show
evidence of deterioration because of age or contamination shall not be used (see 6.3.2).
Containers that have not previously been opened shall be checked for damage or leaks and shall
not be opened unless there is evidence of damage.
3.3.4.6 Lubricant testing. The lubricant shall pass the type B-2 tests for lubricating oils
and for greases, semi-fluids, lubricants, and other grease-like materials of MIL-STD-3004.
Additional testing of the principal characteristics likely to affect deterioration is optional.
bearings and bearing parts shall be coated with the lubricant or preservative compound specified
in 3.3.4. Bearings shall be completely preserved so as to obtain a continuous coating on all
surfaces. During or after preservation with the compound, all internal surfaces shall receive
complete coverage. When an operational lubricant (grease or oil) is required, the quantity
applied shall conform to the item description or technical data applicable to the assigned national
12
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business