MATERIAL INTRODUCTION
302 Stainless Steel Spring Wire
Austenitic stainless steel spring wire, density: 7.93 g/cm³.
Discuss your specifications ↗Chemical Composition (wt%)
| Item | Specification / Description |
|---|---|
| C | ≤0.15 |
| Si | ≤1.00 |
| Mn | ≤2.00 |
| P | ≤0.045 |
| S | ≤0.030 |
| Cr | 17.0～19.0 |
| Ni | 8.0～10.0 |
18-8 grade, higher carbon than 304. Work-hardening rate: better than 304, lower than 301
Applicable Standards
| Item | Specification / Description |
|---|---|
| Standard / designation | JIS G4314 |
| Standard / designation | GB/T 4240 |
| Standard / designation | ASTM A313 |
| Standard / designation | EN 10270-3 (1.4319 / S30200) |
Tensile Strength
| Item | Specification / Description |
|---|---|
| Specification | (Cold drawn tempers MPa, finer wire higher strength) |
| ANN (Soft) | 580～780 MPa, good ductility for forming |
| 1/2H (Half hard) | 820～1020 MPa |
| SH (Spring hard) | 1150～1600 MPa |
| Note | Not hardenable by quenching. Elasticity only from cold drawing. Non-magnetic after annealing, weak magnetism after cold drawing. Tensile strength ranking for same diameter: 301＞302＞304＞316 |
Common Surface Finishes
| Item | Specification / Description |
|---|---|
| BA bright finish | mirror bright for cosmetic & tiny precision springs |
| Matte/dull finish | mainstream for springs, better fatigue resistance |
| Pickled finish | low cost general purpose |
Size Range
| Item | Specification / Description |
|---|---|
| Diameter | 0.05～8.0 mm, tight tolerance down to ±0.002 mm, coils or spools |
Features
- Classic 18-8 stainless spring wire. Higher carbon than 304 gives stronger spring force. Corrosion resistance slightly lower than 304, better than 301
- Resists atmosphere, fresh water and weak acid. Not suitable for chloride / salt spray environment (choose 316)
- Fair weldability, but cold-work strength disappears after welding; not for load-bearing welded springs
- Cost sits between 304 and 301, balanced all-round spring material
Applications
General compression, tension & torsion springs, hardware springs, wire mesh, hose braiding, electrical elastic wires, sanitary springs without salt spray
Material Selection Guide
302 spring wire: stronger force than 304, better corrosion resistance than 301, balanced general grade
301 spring wire: fastest work-hardening, highest spring force, poorest corrosion resistance
304 spring wire: better corrosion resistance, lower spring force, most popular
316 spring wire: Mo added for salt spray & seawater, lowest spring force, premium price