Stainless steel expansion bolt

Hardening process of blue zinc plating                                                                           

Flat without burr
The surface is smooth and burr-free, with high quality and durability.                              Fine thread
Deep thread without burr, uniform stress without tooth loss, clear and complete screw thread.                                                                                                                                Hardening process of blue zinc plating
Uniform coating, high hardness, bright and clean screws as new, corrosion-resistant, rust-proof, durable.                   

High quality carbon steel process,Surface zinc plating process