Linear guide is used for high-precision or high-speed linear reciprocating motion, and can bear a certain torque, can achieve high-precision linear motion under high load. The function of linear guide rail movement is to support and guide the moving parts, according to the given direction to do reciprocating linear movement. According to the friction properties, linear motion guide can be divided into sliding friction guide, rolling friction guide, elastic friction guide, fluid friction guide and so on. Linear bearings are mainly used in automated machinery, such as machine tools imported from Germany, bending machines, laser welding machines, etc., of course, linear bearings and linear shafts are used together. For example, linear guides are mainly used in mechanical structures with high precision requirements, and there is no intermediate medium between the moving components and fixed components of linear guides, and rolling steel balls are used.