What are the standards for fastener products? What are the classifications of wire rods for auto parts? Let's answer these two questions below, and the specific answers are as follows.

1. What are the standards for fastener products?

Answer: Each fastener product must involve some standards in several aspects, the specific ones are:

(1) Standards for fastener product size: specify the content of the basic size of the product; for threaded products, it also includes the basic size of the thread, the end of the thread, the shoulder distance, the retraction groove and chamfering, and the end of the externally threaded parts. size and other aspects.

(2) Standards for the technical conditions of fastener products, including standards for the following aspects:

A. Standards for fastener product tolerances: specify the tolerances of product dimensions and form and position tolerances.

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

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

D. Standards for surface treatment of fastener products: specify the types of product surface treatment and specific requirements.

E. Standards for fastener product testing: Specify the content of the above-mentioned performance requirements for testing.

(3) Standards for fastener product acceptance inspection, marking and packaging: specify the acceptable quality level and sampling plan of random inspection items when the product leaves the factory for acceptance, as well as the content of product marking methods and packaging requirements.

(4) Standards for fastener product marking methods: specify the content of complete product marking methods and simplified marking methods.

(5) Standards for other aspect