Stainless SteelBar/Rod
Description (English)
SUS 440C (UNS S44004, DIN 1.4125) is a high-carbon martensitic stainless steel that achieves the highest hardness of any stainless steel — up to 60 HRC after quenching and tempering — combined with good corrosion resistance in fresh water and mild media. Vertex Alloy supplies 440C round bars from 3 to 300 mm diameter in annealed, quenched & tempered, peeled, ground and polished conditions to ASTM A276 and AMS 5630, with EN 10204 3.1 certificates. Typical applications include ball and roller bearings, premium knife blades, surgical and dental instruments, valve seats and balls, pump shafts and plastic mold inserts. Free-machining 440F and low-carbon alternatives available on request.
Size Range
- Dia.3 – 300 mm
- L1000 – 6000 mm
- Available on request
Grade Specification
| System | Value |
|---|---|
| 🇯🇵 JIS | SUS 440C |
| ASTM / AISI | 440C / S44004 |
| DIN / EN | 1.4125 / X105CrMo17 |
| 🇨🇳 GB | 9Cr18Mo / 102Cr17Mo |
| ISO | X105CrMo17 |
Chemical Composition
| Element | Value |
|---|---|
| C | 0.95 – 1.20 |
| Si | ≤ 1.00 |
| Mn | ≤ 1.00 |
| P | ≤ 0.040 |
| S | ≤ 0.030 |
| Cr | 16.00 – 18.00 |
| Mo | ≤ 0.75 |
| Ni | ≤ 0.60 |
| Fe | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength (Annealed) | ≥ 758 MPa |
| Yield Strength (Annealed) | ≥ 448 MPa |
| Elongation (Annealed) | ≥ 14 % |
| Hardness (Annealed) | ≤ 255 HB |
| Hardness (Quenched & Tempered) | ≥ 58 HRC |
| Max Working Hardness | 60 HRC |
| Impact Energy (Annealed) | ≥ 16 J |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | - | 7.74 g/cm³ |
| Melting Point | - | 1370 – 1480 °C |
| Specific Heat Capacity | - | 460 J/(kg·K) |
| Thermal Conductivity | - | 24.2 W/(m·K) |
| Electrical Resistivity | - | 0.60 μΩ·m |
| Elastic Modulus | - | 200 GPa |
| Thermal Expansion (20–100 °C) | - | 10.2 × 10⁻⁶ /K |
| Magnetic | - | Yes |
Applications
- Bearings
- Cutlery
- Medical
- Valves
- Molds
- Aerospace
- Marine
- Textile