The retaining ring is standard. The retaining ring is a ring-shaped part fastened to the shaft, which can prevent other parts mounted on the shaft from moving. It is made by wire punching process and has a circular cross-section. Standard parts refer to the commonly used parts (parts) such as threaded parts, keys, pins, rolling bearings, etc. In a broad sense, it includes standardized fasteners, connectors, transmission parts, seals, hydraulic components, pneumatic components, bearings, springs and other mechanical parts. In a narrow sense, only standardized fasteners are included. The standard part commonly known in China is the abbreviation of standard fastener, which is a narrow concept, but the existence of a broad concept cannot be ruled out. In addition, there are industry standard parts, such as automobile standard parts, mold standard parts, etc., which also belong to generalized standard parts.