55 vs 1055
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.
55
Carbon Steel
55 is the GB/T 699 equivalent of AISI 1055 / JIS S55C, bridging machinery and spring applications with plain-carbon economics.
Standards: DIN 1.0535 (C55) · AISI 1055 · JIS S55C · GB 55 (GB/T 699)
1055
Carbon Steel
1055 is a high-medium carbon steel for parts needing a hard, wear-resistant surface with a resilient core. It overlaps the lower spring range and is common in agricultural and hand-tool applications.
Standards: DIN 1.0535 (C55) · AISI 1055 · JIS S55C · GB 55
Chemical composition compared (%)
| Element | 55 | 1055 |
|---|---|---|
| C | 0.52–0.60 | 0.50–0.60 |
| Si | 0.17–0.37 | — |
| Mn | 0.50–0.80 | 0.60–0.90 |
| P | ≤0.035 | ≤0.040 |
| S | ≤0.035 | ≤0.050 |
| Cr | ≤0.25 | — |
Properties compared
| Property | 55 | 1055 |
|---|---|---|
| Tensile strength | ≥645 MPa (GB/T 699 reference, normalized blank) | 650–780 MPa (normalized, typ.) |
| Yield strength | ≥380 MPa (reference) | — |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
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: 55 · 1055. Substitution decisions for certified parts stay with the design authority.