440B vs 440C
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.
440B
Stainless Steel
440B is the middle member of the 440 series, with carbon between 440A and 440C, balancing edge hardness against toughness and corrosion resistance in cutlery and bearing applications.
Standards: AISI 440B · JIS SUS440B
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
Chemical composition compared (%)
| Element | 440B | 440C |
|---|---|---|
| C | 0.75–0.95 | 0.95–1.20 |
| 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 | 440B | 440C |
|---|---|---|
| Delivery condition | Annealed (hardened for use) | Annealed (hardened for use) |
| Hardness (hardened) | 56–59 HRC | 58–60 HRC |
| Tensile strength | 740–1960 MPa (condition dependent) | 760–2030 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: 440B · 440C. Substitution decisions for certified parts stay with the design authority.