1、 Standard parts refer to the common parts (parts) that have been completely standardized in structure, size, drawing, marking, etc. and produced by professional factories, such as threaded parts, keys, pins, rolling bearings, etc.
2、 In a broad sense, it includes standardized fasteners, connectors, transmission parts, seals, hydraulic components, pneumatic components, bearings, springs and other mechanical parts. Only standardized fasteners are included in the narrow sense. The commonly known standard part in China is the abbreviation of standard fastener, which is a narrow concept, but cannot exclude the broad concept
3、 The narrow sense standard part is the standardized fastener, which is actually a kind of connector (connector). However, because of its wide range of applications, it is only one kind in actual use, even referred to as standard part for short