Analysis of fastener

Release time：2021-01-23　　　　 Time to browse

　　Fastener, also known as standard parts in the market, is the general term of a kind of mechanical parts used when two or more parts (or components) are tightly connected into a whole. It is characterized by a wide variety of specifications, different performance and uses, and a high degree of standardization, serialization and generalization. Fastener is the most widely used mechanical basic parts, and the demand is very large.

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　　standard

　　1. Standard of fastener product size: specify the content of basic product size; products with thread also include basic thread size, thread ending, shoulder distance, undercut and chamfer, end size of external thread parts, etc.

　　2. Standard of technical conditions for fastener products. It also includes the following standards:

　　a) Standard of fastener product tolerance: specify the content of product dimension tolerance and geometric tolerance.

　　b) Standards for mechanical properties of fastener products: specify the marking method of mechanical property grade of products and the contents of mechanical property items and requirements; some fastener products change this content to the contents of material properties or working properties of products.

　　c) Standards for surface defects of fastener products: specify the types and specific requirements of surface defects.

　　d) Standards for surface treatment of fastener products: specify the types and requirements of surface treatment.

　　e) Standard of fastener product test: specify the test contents of the above performance requirements.

　　3. Standards for acceptance inspection, marking and packaging of fastener products: specify the qualified quality level and sampling plan of spot check items, as well as the content of product marking method and packaging requirements.

　　4. Standard of fastener product marking method: specify the content of complete marking method and simplified marking method.

　　5. Other standards of fasteners: such as fastener terminology standards, fastener product weight standards, etc.