Purpose
The methods in accordance with this standard are intended to determine the characteristic values of lubricants with additives which should allow high surface pressure in the mixed friction area between surfaces moved in relation to each other. The method gives little correlation to the behavior of the lubricants in real applications.
Brief description of the method
The lubricant is tested in a four-ball system, which consists of a rotating ball (running ball), which slides on three balls which are identical to it (stationary balls). The test loads may either be increased gradually until the four-ball system seizes up or the ball imprint diameters of the three stationary balls shall be measured with constant test load after a set test period.
| DIN | ASTM | IP |
|---|---|---|
| 51350 Part 2 (weld load, fluids) | D-2783 (weld load, fluids) | 239 |
| 51350 Part 3 (wear, fluids) | D-4172 (wear, fluids) | |
| 51350 Part 4 (weld load, greases) | D-2596 (weld load, greases) | |
| 51350 Part 5 (wear, greases) | D-2266 (wear, greases) |