Overview
CgoodSteel Seat Belt Steel Strip is engineered to meet the stringent safety and performance requirements of automotive seat belt retractor systems. As a critical component in occupant restraint systems, our strip material delivers exceptional strength, fatigue resistance, and dimensional consistency to ensure reliable retraction force and long-term durability under repeated cyclic loading and varying temperatures.
We supply globally to seat belt manufacturers and Tier‑1 automotive suppliers, providing tailored solutions that comply with international safety standards such as FMVSS 209, ECE R16, and OEM‑specific specifications.
Key Performance Features
- Ultra-High Fatigue Life – withstands over 50,000 retraction cycles without failure
- High Tensile & Yield Strength – ensures consistent retractor spring force throughout vehicle lifespan
- Excellent Flatness & Edge Quality – enables smooth, jam‑free coil winding in retractor assemblies
- Controlled Surface Roughness – reduces wear between coils and housing
- Stable Mechanical Properties Across Temperatures – performs reliably from ‑40°C to +85°C
- Customizable Spring Back Characteristics – optimized for specific retractor designs
Material Grades & Specifications
| Grade Standard | Recommended Grades | Typical Hardness (HRC) | Thickness Range (mm) | Width Range (mm) |
|---|---|---|---|---|
| DIN / EN | CK67, CK75, C75 | 42‑50 (H&T) | 0.20 – 1.20 | 6 – 50 |
| AISI / SAE | 1065, 1074, 1075 | 42‑50 (H&T) | 0.20 – 1.20 | 6 – 50 |
| Alloy Steels | 51CrV4, 50CrV4 | 45‑52 (H&T) | 0.25 – 1.50 | 8 – 60 |
| Special High‑Fatigue Grades | Custom‑enhanced C75, C75Cr1 | 44‑48 (H&T) | 0.15 – 1.00 | 5 – 40 |
Technical Properties
| Property | Test Method | Typical Value |
|---|---|---|
| Tensile Strength (Rm) | ISO 6892‑1 | 1,450 – 1,800 N/mm² |
| Yield Strength (Rp0.2) | ISO 6892‑1 | 1,350 – 1,700 N/mm² |
| Fatigue Limit (at 10⁷ cycles) | DIN 50100 | ≥ 650 N/mm² |
| Hardness Uniformity | HRC, full‑strip mapping | ±1.5 HRC max deviation |
| Decarburization Depth | Metallographic | ≤ 0.02 mm (max) |
| Flatness (over 1 m) | Laser scanning | ≤ 0.5 mm |
| Surface Roughness (Ra) | Profilometer | 0.4 – 1.0 µm (adjustable) |
Application in Seat Belt Systems
Our steel strip is primarily used in the retractor spiral spring (also known as the rewind spring), which provides the rotational force to retract the seat belt webbing smoothly and store it neatly. Key performance requirements include:
- Consistent torque output across the entire retraction stroke
- Resistance to permanent set after long‑term compressed storage
- Corrosion resistance to withstand interior cabin environmental exposure
- Noise‑free operation through precision edge conditioning and surface control
Production Process & Quality Control
- Material Selection – Prime steel sourced from certified mills with full traceability
- Precision Cold Rolling – Tight thickness tolerance (typically ±0.01 mm)
- Continuous Heat Treatment – Controlled atmosphere hardening & tempering for uniform microstructure
- Surface Finishing – Optional bright, polished, or phosphated surfaces
- Slitting & Edge Conditioning – Burr‑free rounded edges to prevent inter‑coil abrasion
- 100% Testing – Including:
- Fatigue cycling on simulated retractor test rigs
- Torque‑displacement curve verification
- Salt‑spray corrosion testing per ASTM B117
Customization Capabilities
We collaborate with your engineering team to tailor the strip to your retractor design:
- Custom torque‑displacement profiles
- Special edge shapes (round, trapezoidal, deburred)
- Pre‑cut lengths or precision‑slit coils
- Anti‑friction and anti‑corrosion coatings
- Packaging – wax‑paper interleaving, VCI film, or custom reel packaging
Prototype support and low MOQ available for development projects.
Compliance & Certification
- Meets material specifications of major seat belt suppliers (Autoliv, ZF‑TRW, Joyson Safety Systems, etc.)
- Compatible with ISO 9001:2015 and IATF 16949 quality management systems
- Material certifications (3.1 or 3.2 per EN 10204) provided with each shipment
Why Choose CgoodSteel for Seat Belt Steel Strip?
✅ Specialized in automotive safety‑critical strip applications – over 15 years of seat belt spring supply experience
✅ In‑house fatigue and torque testing – we simulate real retractor performance before shipment
✅ Deep collaboration with retractor manufacturers – understanding of system‑level requirements
✅ Flexible, responsive supply – from prototype coils to just‑in‑time production volumes
✅ Global logistics support – reliable delivery to seat belt plants worldwide