440C vs 440A
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
440C
Stainless Steel
440C is a high-carbon martensitic stainless capable of the highest hardness of any standard stainless grade, used for bearings, knife blades and wear parts. Its large chromium carbides give edge retention but limit toughness and corrosion resistance relative to its chromium content.
Standards: DIN 1.4125 · AISI 440C · JIS SUS440C · GB 102Cr17Mo
440A
Stainless Steel
440A is the lowest-carbon member of the 440 high-carbon martensitic series, trading a little attainable hardness for toughness and corrosion resistance. It is used for cutlery and dental and surgical instruments.
Standards: AISI 440A · JIS SUS440A · GB 68Cr17
Chemical composition compared (%)
| Element | 440C | 440A |
|---|---|---|
| C | 0.95–1.20 | 0.60–0.75 |
| Si | ≤1.00 | ≤1.00 |
| Mn | ≤1.00 | ≤1.00 |
| P | ≤0.040 | ≤0.040 |
| S | ≤0.030 | ≤0.030 |
| Cr | 16.00–18.00 | 16.00–18.00 |
| Mo | ≤0.75 | ≤0.75 |
Properties compared
| Property | 440C | 440A |
|---|---|---|
| Delivery condition | Annealed (hardened for use) | Annealed (hardened for use) |
| Hardness (hardened) | 58–60 HRC | 55–58 HRC |
| Tensile strength | 760–2030 MPa (condition dependent) | 725–1930 MPa (condition dependent) |
| Density | 7.70 g/cm³ | 7.70 g/cm³ |
| Magnetic | Yes | Yes |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: 440C · 440A. Substitution decisions for certified parts stay with the design authority.