Fasteners

Screw, usually used alone, with pre-drilled holes to achieve locking effect (sometimes used with washers). Bolts are used with nuts.
A nut, also known as a nut, is a fixing tool with a hole in the center and a thread on the inside of the hole. Lugs are often shared with screws of similar sizes to fix the relevant joint parts.
The washer provides the function of preventing loosening and protecting the surface of the locking piece. If the surface of the locking piece is uneven or the hole diameter is large, the washer can increase the contact surface to achieve the anti-loosening effect.

Specification
Material：Carbon steel / Galvanized heat treatment / Alloy steel / Stainless steel