Cold Heading Fasteners for Auto

Our cold heading fasteners for auto are made from cold-heading alloy steel. The material grades are ML40Cr and ML35CrMo. These have the right carbon and alloy mix for cold forming. The plastic formability is good. They do not crack during cold heading. After heat treatment, they become very strong. You can find our cold heading fasteners for auto on control arms, subframes, steering knuckles, and shock absorber brackets. One of our customers builds chassis modules. He needs 500,000 high-strength bolts every month. Batch stability is his top concern. One broken bolt could cause a recall. We used automotive-grade cold heading alloy steel. Our tooling precision reached IT8. Hardness variation after heat treatment was within plus/minus 2HRC. He has had zero complaints for two years.

Our cold heading machines are multi-station. They do heading, reducing, chamfering, and thread rolling all at once. This gives good size consistency. We make 1.5 million pieces per day. So we can easily fill any large order. Our cold heading fasteners for auto meet GB/T 6478, QC/T 598, and GB/T 5267.2. Key assembly dimensions hold IT8 grade. Mechanical performance is stable at 8.8 to 10.9 grade. For corrosion, dacromet zinc-aluminum coating gives at least 120 hours of salt spray. Cold heading cracks and folds are controlled below 1ppm. We check chemistry of every raw material batch. We also do magnetic particle inspection for surface cracks. Hardness and torque are sampled after heat treatment. All records are kept for at least five years.