ASTM D1261 Effect of Grease on Copper (a.k.a. the bomb copper test)
Copper is malleable, ductile, resistant to corrosion, and an excellent conductor of heat and electricity. It is therefore used in numerous electrical and mechanical applications. If copper is exposed to lubricating grease and the grease reacts with the copper, the integrity of the system may be compromised. This test evaluates changes in copper test coupons exposed to lubricating grease under accelerated storage conditions.
Copper strips are cleaned, polished and half inserted into the test grease. The grease is then placed in a pressure vessel, pressurized with oxygen and heated to the test temperature. At the end of the test time the copper is examined for discoloration, etching and corrosion. If the grease-exposed copper appears to show no detrimental effects or is the same or better than the copper not immersed in the grease, a “pass” is reported.
Note: This test is considered obsolete by ASTM. It is still offered by Petro-Lube as a service to our clients.