EP on a grease stands for extreme pressure. EP greases contain additives that protect metal surfaces when the load is so high that the normal lubricant film can break down. Without that protection, surfaces can scuff or even weld together at contact points.
A common way to measure this is the four-ball weld load test (ASTM D2596), which determines the load at which steel test balls weld together. The higher the value, the more load the grease can carry. Interflon Food Grease EP has a four-ball weld load of 450 kg.
An EP rating alone does not determine whether a grease suits an application. Base oil viscosity, speed and operating temperature are just as important.
