Custom Spiral Springs - Stabilized Against Permanent Set
Custom Spiral Springs
,Stabilized Spiral Springs
,Wire Forming Springs
Custom Spiral Springs - Stabilized Against Permanent Set
Product Introduction
TOPONE produces custom stainless steel spiral springs wound from certified spring wire in 0.15-12 mm diameters. Every spring design is checked for one failure mode that specs rarely mention: permanent set. We stabilize critical springs before shipment so the free length and rate you measured on the sample stay valid in production batches.
Product Specifications
| Parameter | Specification |
|---|---|
| Product | helical / spiral springs made to drawing |
| Wire grade | 302 / 304 / 316 stainless spring wire |
| Wire diameter | 0.15-12 mm |
| Coil direction | right-hand or left-hand, per drawing |
| Ends | closed, open, ground or squared |
| Standards | ASTM A580 wire, EN 10270-3, JIS G4314 |
| Documentation | 3.1 MTC for the incoming wire lot |
What Permanent Set Is
Set is the length a spring fails to return after being deflected. When a helical spring is wound, the wire surface carries residual bending stresses left over from coiling. On the first strong compression these stresses exceed the elastic limit at the outer fibre, the wire yields slightly, and the spring loses free length and force. A spring that reads 50 N on the first test can read 46 N on the third if it was never stabilized.
How Stabilizing (Scragging) Works
- The finished spring is compressed - or torsion springs are wound - beyond the maximum deflection it will see in service, deliberately forcing the set to occur in the workshop.
- After unloading, the spring relaxes back and further deflections stay elastic, so the rate becomes repeatable.
- For springs that run hot, low-temperature heat treatment at 200-250 degrees C for 30-60 minutes both relieves coiling stress and completes the stabilization.
- The process is verified by measuring load at working length before and after treatment.
When to Ask for It
- Springs working near 70 percent or more of the wire's elastic capability.
- Valve, switch and sensor springs whose force must not drift over life.
- High-temperature service, where coiling stress relief is needed anyway.
- Any spring specified with a tolerance on rate or free length after installation.
Applications
- Valve and actuator return springs
- Electrical switch and contact springs
- Precision measuring and sensor mechanisms
- Industrial machinery and appliance springs
Product Advantages
- Optional scragging and stress relief documented on the inspection report
- Load tested at working length on sampled springs of each batch
- Certified wire with full traceability to the mill certificate
- Made to customer drawing with consistent coil geometry
Quality Control
Wire diameter, coil diameter, free length and rate are checked per sampling plan, and load-at-length is verified after stabilization. Each batch ships with the wire 3.1 MTC and, when requested, the spring inspection report.
Selection and Ordering Notes
- Send the drawing with wire diameter, coil diameter, free length and rate.
- State the maximum working deflection and service temperature.
- Tell us whether the spring must be delivered pre-set or as-wound.
- Confirm end type and any grinding requirement.
- Request load-at-length data if force tolerance is critical.
