What are 4 PCS fix bolts?

4 PCS fix bolts are also known as: 4 PCS anchor bolts. Also called expansion bolts and explosive screws, they are generally used in engineering construction, bridges, ships, automobiles, etc. The grades of expansion bolts are divided into: 45, 50, 60, 70, and 80 stainless steel expansion screws.

Mainly divided into austenite A1, A2, A4, martensite and ferrite C1, C2, C4.