Product Description
The processing of bolts and nuts begins with material selection, typically high-quality carbon steel, stainless steel, or alloy steel, chosen based on application requirements for strength and corrosion resistance.
First, raw materials undergo cold heading, a process where metal rods are cut to length and shaped into blanks using dies under high pressure. This forms the basic shape of screws (with heads) and nuts (with hexagonal or other profiles) efficiently, enhancing material density.
For screws, thread rolling follows. This cold-forming method presses threads into the blank using rotating dies, creating precise, strong threads without removing material. Nuts undergo tapping, where a tap cuts internal threads, ensuring compatibility with corresponding screws.
Heat treatment is crucial for durability. Screws and nuts are often quenched and tempered to harden the material, improving tensile strength and wear resistance. Surface treatment comes next-options include galvanizing (zinc plating for corrosion resistance), chrome plating (for a decorative finish), or phosphating (to enhance adhesion for painting).
Quality checks are integrated throughout: dimensional inspections (using calipers, thread gauges) ensure compliance with standards, while hardness tests verify heat treatment effectiveness. Final cleaning removes debris, preparing the parts for packaging and distribution. This streamlined process ensures screws and nuts meet strict performance and precision requirements for industrial, construction, and consumer applications.
