Material Certificate — SCM435 Cold Heading & Cold Extrusion Steel Hot-Rolled Wire Rod
| Item | Details |
|---|---|
| Manufacturer | Wuhu Xinxing Ductile Iron Pipe Co., Ltd. |
| Certificate No. | 20250528200310 |
| Customer | Wenzhou Xiongjing Economic & Trading Co., Ltd. |
| Steel Grade | SCM435-FF |
| Specification | WXJX-2019-007 (Internal Standard) |
| Size | Φ8mm |
| Delivery Status | Hot-Rolled |
| Date of Issue | May 28, 2025 |
| Wagon No. | 1799570 |
Chemical Composition (Typical Values)
| Element | Value (%) | Significance |
|---|---|---|
| C (Carbon) | 0.38 | Medium carbon — provides strength and hardness |
| Si (Silicon) | 0.19 | Deoxidizer, improves strength |
| Mn (Manganese) | 0.68 | Improves hardenability and tensile strength |
| P (Phosphorus) | 0.008 | Low level — good for cold formability |
| S (Sulfur) | 0.002 | Very low — excellent machinability and ductility |
| Cr (Chromium) | 1.00 | Key element — improves hardenability, wear resistance, and strength |
| Ni (Nickel) | 0.02 | Trace — minimal impact |
| Cu (Copper) | 0.02 | Trace — minimal impact |
| Mo (Molybdenum) | 0.18 | Improves high-temperature strength and creep resistance |
| Al (Aluminum) | 0.026 | Grain refiner, deoxidizer |
Key Quality Indicators
| Test | Result | Interpretation |
|---|---|---|
| Decarburization | 0.000 mm | Excellent — No surface decarburization, critical for cold forming quality |
| 1/2 Cold Upset Forging | Pass | Material withstands 50% deformation without cracking |
| 1/3 Cold Upset Forging | Pass | Material withstands 33% deformation without cracking |
| General Porosity | 0.5, 0.5 | Minor segregation — acceptable for this grade |
| Center Porosity | 0.5, 0.5 | Minor center porosity — within spec |
| Dimensions & Surface Quality | Pass | Meets dimensional and surface requirements |
Notes / Recommendations
- Usage Timing: For optimal cold forming performance, use 10 days after production date in spring/summer; 15 days after in autumn/winter. This allows sufficient aging for hydrogen diffusion and stress relief.
- Dispute Handling: If any quality issues arise, please specify steel grade, batch number, size, delivery date, and reason. Preserve the physical material. Contact: 0553-5627535.
Summary: Why SCM435 Matters for High-Strength Fastener Manufacturing
This is a high-quality SCM435 alloy steel wire rod (equivalent to AISI 4137 / 4140 in US standards, or 34CrMo4 in European standards) specifically produced for cold heading and cold extrusion applications.
Key advantages for fastener manufacturing:
- Very low sulfur (0.002%) and phosphorus (0.008%) → excellent cold formability
- Zero decarburization → consistent surface hardness after heat treatment
- Passes cold upset tests → suitable for complex bolt/nut forming without cracking
- Chromium + Molybdenum content → good hardenability for quench & temper applications
Typical applications: High-strength bolts, studs, and fasteners requiring heat treatment (e.g., ASTM A193 B7/B7M class products).