VITROLUBE NPI-425

This lubricant contains MoS2, and other lubricating pigments in a polymide high temperature resin and was developed by Midwest Research Institute, Kansas City, Missouri in connection with a contract with the NASA Marshall Space Flight Center, Huntsville, Alabama. NPI has been licensed by MRI to formulate, apply and market this lubricant since 1968. This lubricant was developed for use at temperatures up to +500°F and in hard vacuum environments. NPI-425 has excellent wear life, having 3 to 5 times longer wear life than MIL-L-8937 lubricants at room temperature and 5 to 10 times longer at 450 F. It passes ASTM E595 outgassing requirements and is radiation resistant. The nominal thickness of this lubricant is 0.0002 to 0.0004 inches and is cured for 1 hour at +300°F followed by 1 hour at +575°F and, therefore, would not be considered suitable for use on some metallic substrates such as aluminum. Tests have shown, however, that acceptable performance can be obtained by increasing the +300°F cure time to 5 hours and eliminating the +575°F cure procedure. Tests also show that this lubricant has a very constant and low coefficient of friction compared to other lubricants.

Wear life testing is routinely conducted using the Falex Pin and V-Block tester, per ASTM D2625-69 Procedure A. base material: V-Blocks AISIC 1137 Steel, Pins SAE 3135 Steel; average wear life is 7.65 hours. Load Carrying Capacity tests have also been run per ASTM D2625-69 Procedure B with test pieces reaching the 4500 lb load, and continuing to run for approximately twenty five minutes before failure. More information about the Falex Pin and V-Block tester can be found in the Wear Life Testing information area under NPI-1220.