Product Introduction
Specialized in manufacturing high-performance stainless steel strips for spring applications, our products feature Alloy 301 and 304 in various temper conditions: Soft Anneal (SA), 1/4 Hard (1/4H), 1/2 Hard (1/2H), 3/4 Hard (3/4H), and Full Hard (FH). Engineered to meet the strict demands of spring fabrication, these strips offer exceptional elasticity, fatigue resistance, and dimensional stability. Alloy 301 is renowned for its high tensile strength and formability in spring applications, while 304 provides superior corrosion resistance for environments requiring durability. The controlled annealing and cold-working processes ensure precise hardness levels, making them ideal for compression springs, torsion springs, extension springs, and precision spring components across industries such as automotive, electronics, aerospace, and medical devices.
Technical Parameters
| Parameter | Details |
| Material Grades | 301 (UNS S30100), 304 (UNS S30400) (AISI/ASME standards) |
| Temper Conditions | Soft Anneal (SA), 1/4 Hard (1/4H), 1/2 Hard (1/2H), 3/4 Hard (3/4H), Full Hard (FH) |
| Thickness | 0.1mm - 2.0mm (Tolerance: ±0.01mm for thickness ≤1mm; ±0.02mm for >1mm) |
| Width | 10mm - 610mm (Slit cutting tolerance: ±0.1mm for width ≤200mm; ±0.2mm for >200mm) |
| Hardness (HV) | SA: 140-200 1/4H: 250-320 1/2H: 320-380 3/4H: 380-450 FH: 450-550 |
| Tensile Strength (MPa) | 301: SA: 520-750 1/4H: 750-1000 1/2H: 1000-1300 3/4H: 1300-1500 FH: 1500-1700 304: SA: 550-800 1/2H: 850-1100 FH: 1100-1350 |
| Elongation at Break | SA: ≥35% (301), ≥40% (304) FH: ≥10% (301), ≥15% (304) |
| Surface Finish | 2B (Standard), BA (Bright Annealed), No.4 Polish, Anti-Fingerprint Coating |
| Edge Quality | Burr-free, smooth edge (Ra ≤1.6μm) with precision slitting technology |
Specifications
Dimensions & Coil Details
- Coil Weight: 50kg - 1500kg per coil (Customizable for spring wire applications)
- Inner Diameter: 305mm (Narrow strips) / 508mm (Wide strips)
- Outer Diameter: Up to 1200mm (Subject to thickness and temper)
- Straight Strips Length: 500mm - 6000mm (Precision-cut for spring blanks)
Grade & Temper Applications
| Grade | Temper | Key Properties | Typical Spring Applications |
| 301 | SA | High ductility for forming complex spring shapes | Pre-forming of compression springs |
| 301 | 1/4H-3/4H | Balanced elasticity and formability | Torsion springs, automotive valve springs |
| 301 | FH | Maximum tensile strength and spring resilience | Heavy-duty industrial springs, aerospace springs |
| 304 | SA-1/2H | Corrosion resistance with moderate elasticity | Medical device springs, marine-grade springs |
| 304 | FH | High-strength corrosion resistance | Springs in chemical environments or food processing |
Product Features
- Precision Temper Control:
- Consistent hardness across the strip width and length ensures uniform spring performance.
- Custom temper grades available to match specific spring design requirements (e.g., load-bearing capacity, deflection).
- Superior Spring Properties:
- High elastic limit and fatigue resistance (≥1 million cycles under standard load for 301 FH).
- Low relaxation rate under prolonged stress, ideal for long-life spring applications.
- Tight thickness and width tolerances reduce spring manufacturing waste and improve assembly precision.
- Flatness tolerance: ≤3mm/m for strips ≥0.5mm thickness.
- Smooth, defect-free surfaces minimize stress concentrations during spring coiling.
- Optional anti-fingerprint coatings protect against corrosion during storage and handling.
- Soft Anneal and 1/4H tempers allow intricate coiling and shaping without cracking.
- Full Hard temper retains shape after forming, reducing post-processing heat treatment needs.
Standards Compliance
- ASTM A666 (Stainless Steel Strip – Cold-Rolled)
- ASTM A313 (Stainless Steel Spring Wire)
- JIS G4313 (Stainless Steel Spring Strip)
- EN 10270-3 (Stainless Steel Spring Wire and Strip)
- Mill Test Certificates (MTC) including chemical composition, mechanical properties, and temper compliance.
- Optional (Third-party inspection reports) for critical applications.
Packaging Solutions
- Inner layer: Wrapped with VCI (Volatile Corrosion Inhibitor) paper or PE film to prevent oxidation.
- For high-temper strips (3/4H/FH), edges are protected with foam strips to avoid scratching.
- Coils ≤500kg: Packed in reinforced cardboard boxes with corner protectors.
- Coils >500kg: Palletized on wooden crates with steel strapping and moisture-absorbing packets.
- Clear identification of grade, temper, thickness, width, and heat number for traceability.
- Custom labels available with customer logos or specific handling instructions.
After-Sales Service
- 100% inspection for hardness, dimensional accuracy, and surface defects using digital profilometers and tensile testing.
- Spring performance testing (load-deflection curve) available upon request.
- 12-month warranty against temper inconsistency, surface flaws, or dimensional non-conformance under normal storage and use.
- Spring design consultation: Assistance with material selection, temper recommendation, and stress analysis.
- Processing guidance: Tips for coiling, heat treatment, and surface finishing to optimize spring performance.
- Full refund or free replacement for non-conforming products confirmed by joint inspection.
- Rapid response within 48 hours to customer quality inquiries.
For custom spring strip requirements or to request samples, contact our technical sales team with your spring design specifications (e.g., wire diameter, spring type, load requirements). We specialize in delivering tailored solutions that enhance spring reliability and performance in the most demanding applications.
