Steel base copper-plastic bushing is used for low load, and bimetal bushing can be used for high load.
The bushes made of friction-reducing materials in sliding bearings are also called bearing bushes and bushes. Usually cast on the inner surface of the bearing bush, mainly to reduce costs and save valuable wear-reducing materials. Thickness 0.5-6mm, used for large size or important bearings. The bearing bushing is mainly used to replace the wear of the shaft. In addition, it also supports the operation of the shaft, reducing friction, wear and vibration.
The earliest sliding and rolling element bearings were made of wood. Ceramics, sapphire or glass are also used, steel, copper, other metals, plastics (such as nylon, bakelite, Teflon and UHMWPE) are commonly used.
From heavy-duty wheel axles and machine tool spindles to precision internal watch parts, rotary bearings are required in many applications. The simplest rotary bearing is a bushing bearing, which just accommodates a bushing sandwiched between the wheel and the axle. This design was subsequently replaced by rolling bearings, which used many cylindrical rollers to replace the original bushings, and each rolling element was like a separate wheel. The earliest put into practice rolling bearings with cages were invented by watchmaker John Harrison in 1760 for making H3 chronographs.