Our Spring Manufacturing Process
At GL Springs, every spring is produced through a controlled, standardized manufacturing process — from certified raw material to finished, inspected part. Disciplined process control at each stage is what delivers the consistency and repeatability that automotive, medical, and electronics customers depend on.
Step 1: Material Sourcing & Incoming Inspection
- Source high-quality materials from certified suppliers (stainless steel 304/316, carbon steel SWC/SWP, alloy steel 55CrSi)
- Conduct incoming material inspection (spectral analysis for composition, tensile strength testing)
- Batch number tracking for full traceability
Step 2: Precision Forming (CNC Coiling & Wire Forming)
- Use advanced CNC machines (15-axis for springs, 12-axis for wire formings) for high-precision forming
- Real-time monitoring of production parameters (wire tension, coiling speed, bending angle)
- Custom tooling for complex shapes and special designs
Step 3: Heat Treatment
- Quenching and tempering to enhance hardness, elasticity, and fatigue resistance
- Temperature control to ±5 °C for consistent mechanical performance
- Controlled post-treatment cooling to prevent deformation
Step 4: Finishing
- End grinding for compression springs
- Precision hook forming for tension springs — no deformation, strong load-bearing
- Surface treatments: zinc / nickel plating, Dacromet, black oxide, passivation, powder coating
Step 5: In-Process Quality Control
Quality is checked throughout production, not just at the end. Critical dimensions and loads are monitored at each stage to catch deviations early.→ See our full inspection capability on the Quality Control page.
From Design to Production
Every project starts with engineering review and prototyping before full production. Learn how we optimize each design for performance and cost on our Spring Design page.
Why Manufacture With GL Springs
-20+ years (since 2005) of precision spring manufacturing
-ISO 9001 & IATF 16949 certified, National High-Tech Enterprise
-Controlled process from certified material to finished part
-Prototype to high-volume production, with 7-day sampling
