Full Production Process of High-Strength Truck Wheel Stud & Bolt (10.9/12.9 Grade)

We adopt premium 40Cr/42CrMo alloy steel as raw material, which features uniform internal texture, strong toughness and outstanding tensile resistance to cope with heavy vibration and heavy load of trucks.Before formal forming, all steel rods go through descaling, spheroidizing annealing, wire drawing and fixed-length cutting. The preprocessing removes oxide skin and internal stress, improving steel plasticity and avoiding cracking during cold heading or hot forging.

Extrude compact, wear-resistant metric/BSF/UNF threads without cutting. No thread slipping or tooth collapse.

Integral heat treatment is the key process that upgrades ordinary fasteners to high-strength 10.9/12.9 grade wheel bolts. All semi-finished bolts undergo unified quenching and tempering on a fully automatic closed production line after cold heading or hot forging.

We offer multiple surface finishes for different usage scenarios:

1. 1. Phosphating (Black/Gray): Base coating to boost adhesion and light rust prevention.
2. 2. Dacromet: Excellent salt spray resistance, fit for coastal high-corrosion environments.
3. 3. Zinc Plating (White/Yellow): Cost-effective anti-rust finish for standard fasteners.
4. 4. Black Oxide: Matte black surface with wear resistance, economical for general use.

We implement strict full-inspection quality control to guarantee zero defective deliveries. Every batch of wheel bolts undergoes complete testing, covering full dimensional tolerance checks  and core mechanical performance tests.

We adopt combined manual and machine screening to rule out surface defects like cracks, burrs and uneven coatings. For anti-corrosion coated products including Dacromet and zinc plating finishes, we support authoritative SGS salt spray testing to verify their corrosion resistance. All products fully comply with ISO9001 certification, delivering reliable quality for global heavy truck maintenance and replacement.