1566 vs 65Mn
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.
1566
Carbon Steel
1566 is a high carbon, high manganese steel for springs and wear parts needing deeper hardening than 1065 provides. Its chemistry is close to the GB 65Mn concept under the SAE numbering system.
Standards: AISI 1566 · GB 65Mn (near)
65Mn
Carbon Steel
65Mn is China’s manganese spring steel (GB/T 1222): a high carbon steel whose 0.90–1.20% manganese buys real through-hardening at plain-steel prices. It is ubiquitous in Chinese spring, blade and wear-part production.
Standards: AISI 1065/1566 (near) · GB 65Mn (GB/T 1222)
Chemical composition compared (%)
| Element | 1566 | 65Mn |
|---|---|---|
| C | 0.60–0.71 | 0.62–0.70 |
| Mn | 0.85–1.15 | 0.90–1.20 |
| P | ≤0.040 | ≤0.035 |
| S | ≤0.050 | ≤0.035 |
| Si | — | 0.17–0.37 |
| Cr | — | ≤0.25 |
Properties compared
| Property | 1566 | 65Mn |
|---|---|---|
| Tensile strength | 750–900 MPa (normalized, typ.) | 1000–1250 MPa (Q&T, typ.) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Yield strength | — | ≥785 MPa (Q&T reference, typ.) |
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: 1566 · 65Mn. Substitution decisions for certified parts stay with the design authority.