Description
The Workhorse of Spring Applications – 302 Stainless Steel Wire
In over 15 years supplying spring wire to global manufacturers, we’ve found 302 stainless steel wire remains the go-to choice for engineers who need reliable elasticity without compromise. It’s not the flashiest alloy, but its balanced properties solve real-world problems—from automotive valve springs that endure millions of cycles to medical instruments requiring non-magnetic stability.
What makes 302 stand out? The secret lies in its 18-8 chromium-nickel base (17-19% Cr, 8-10% Ni) with just enough carbon (≤0.15%) to maintain strength after cold working. We’ve seen customers switch from 304 when they need higher tensile strength (up to 2,500 MPa in full hard temper) without sacrificing formability. Unlike some suppliers, we control the phosphorus and sulfur content below 0.045%—a critical detail for fatigue resistance.
Where Performance Meets Precision
- Typical diameter tolerance: ±0.01 mm on wires below 1.0 mm, critical for CNC-formed springs
- In salt spray tests, our 302 wire outperforms standard 304 by 20-30% in neutral 5% NaCl environments
- The austenitic structure stays non-magnetic even after heavy cold drawing—essential for MRI components
- We’ve supplied 0.15 mm wire for watch springs that maintain ±5% load variation after 10,000 deflections
Many ask how it handles extreme temperatures. We’ve tested continuous performance from -200°C to 400°C, with only 8-12% strength reduction at the upper limit. For cryogenic applications, the ductility actually improves below -100°C.
Made for Custom Demands
Our ISO 9001-certified facility produces 302 wire in:
– Five tempers: From annealed (1,200-1,500 MPa) to full hard (2,200-2,500 MPa)
– Three surface finishes: Bright drawn (Ra ≤0.8 μm), matte, or coated (zinc, nylon, or custom)
– Coils from 5 kg to 500 kg, spools per DIN 600, or cut-to-length (±0.5 mm tolerance)
As a Chinese manufacturer, we combine competitive pricing with European-level quality control—each batch comes with full EN 10204 3.1 certification. Whether you need 100 kg of 3.0 mm 1/2 hard wire or 5 kg of specialty 0.2 mm full hard, we’ll match your specs without the typical import delays.
Reach out to discuss your project. We’re happy to send samples or walk through technical details—no obligation, just practical advice from people who’ve been in the spring wire business since 2008.
