The main purpose of the test machine is the four-ball friction test machine in the form of sliding friction, under extremely high point contact pressure conditions, to evaluate the bearing capacity of the lubricant. It includes three indexes, such as the maximum non-seizure load PB, sintering load PD, and wear value d. In practical applications, different evaluation indexes can be selected according to different uses of lubricants

Maximum non-seizure load PB: At a certain temperature and speed, the size of the maximum load diameter where the steel ball does not seize under lubrication is the wear mark. The smaller the wear mark, the better the anti-wear ability and lubricity of the grease is good.

The higher the measured value of this index, the better the lubricating performance of the grease.

Sintering load PD: The load is increased step by step at a certain temperature and speed. When the upper steel ball and the lower steel ball are sintered at high temperature due to excessive load, the load that the equipment has to stop running is the sintering load. The higher the sintering load, the description the better the extreme pressure lubrication performance of the grease.

　　Abrasion marks d: Under certain temperature, rotation speed, load and running time, the surface of the load-bearing steel ball wears straight marks due to friction