Timken OK Load is a standardised measurement that indicates the possible performance of extreme pressure (EP) additives in a lubricating grease or oil. The units of measurement are pounds-force or kilograms-force. This measurement is performed using a special test machine and standard block and ring test specimens.
The test machine is based on a machine manufactured by the Timken Company from 1935 to 1972.
The Timken OK Load test methods are ASTM D-2509 for greases and ASTM D-2782 for oils.
There are a few portable versions of smaller testers utilizing similar test methods for public demonstration or for product showcase.