Angular contact bearings are designed to contact angle between the races and the balls is formed when the bearing is in use. Angular contact bearings may be constructed of special materials including stainless steel, plastic, and ceramic hybrid.  They may also be plated; common plating materials are cadmium and chrome. Angular contact bearings can be one directional thrust, double direction thrust, double row, double row maximum capacity angular, duplex thrust, and four-pointed contact. Angular contact bearings are unidirectional thrust bearings that can withstand heavy thrust loads and moderate radial loads. It assembled with a preload, which is applied between the inner race, the bearing ball and the outer race. The preload minimizes or removes gaps between the bearing balls and the inner and outer races.