is a method for determining the extreme pressure (EP) or anti-wear properties of oils and greases. Typically ASTM-D-3233 with a Vee blocks (with a large "V"-shaped notch) are placed on opposite sides of a rotating steel shaft, and the apparatus is immersed in a bath of the test lubricant. Load is automatically increased until seizure occurs. Measurable wear scars are formed on the blocks.

Also see EP additive.