How GL Springs mass-produces 2M+ custom door-checker springs per month in Dacromet-coated alloy steel with 720h salt-spray resistance — at a competitive cost.
Case Details
Project Snapshot
| Component: |
Automotive door-checker (door-limiter) spring |
| Material: |
Alloy spring steel |
| Wire diameter: |
2.4mm |
| Coating: |
Dacromet — 720 h salt-spray corrosion resistance |
| Volume: |
2,000,000+ pcs / month |
Shanghai Guanglei Spring (GL Springs) is the custom spring supplier for a leading automotive door-checker manufacturer. The door checker (door limiter) is the mechanism that holds a car door open at fixed positions; its spring must deliver consistent force and long fatigue life while resisting corrosion in the door-hinge environment — and it must be produced reliably at very high volume and a competitive cost. Here is how we delivered.
The Challenge
Our customer needed a door-checker spring that had to:
- Be produced at 2,000,000+ pieces per month with consistent quality
- Withstand the moisture-exposed door-hinge environment, requiring 720 hours of salt-spray corrosion resistance
- Maintain stable force and dimensional consistency for smooth, repeatable door operation over the vehicle's life
- Hit an aggressive unit-cost target, since door checkers are high-volume, cost-sensitive components
Our Solution
- Material & design: alloy spring steel at 2.4 mm wire diameter, engineered for the required load and fatigue performance
- Surface protection: Dacromet coating delivering 720 hours of salt-spray corrosion resistance
- Mass production: high-speed coiling lines with in-process inspection to hold tolerances consistently across millions of parts
- Cost engineering: optimized design, material usage, and production efficiency to meet the customer's cost-reduction target without compromising durability
→See the product:
Door Check SpringThe Result
- Stable, on-time supply of 2,000,000+ springs per month
- 720 hours salt-spray corrosion resistance achieved through Dacromet coating
- Helped the customer significantly reduce the unit cost of this component, improving the competitiveness of their door-checker assembly
- A long-term, high-volume supply partnership built on consistent quality
