S55C vs S50C
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.
S55C
Carbon Steel
S55C is the higher-carbon member of the JIS G4051 family (AISI 1055 / EN C55 class), used where a carbon steel must take real surface hardness — rails, shafts, gears of moderate duty and wear parts in Asian machinery.
Standards: DIN C55 (1.0535) · AISI 1055 · JIS S55C (JIS G4051) · GB 55
S50C
Carbon Steel
S50C is the JIS medium-carbon steel slightly richer in carbon than S45C/1045, popular in Asian supply chains for machine parts, shafts and mold plates.
Standards: DIN 1.0540 (C50) · AISI 1050 · JIS S50C · GB 50
Chemical composition compared (%)
| Element | S55C | S50C |
|---|---|---|
| C | 0.52–0.58 | 0.47–0.53 |
| Si | 0.15–0.35 | 0.15–0.35 |
| Mn | 0.60–0.90 | 0.60–0.90 |
| P | ≤0.030 | ≤0.030 |
| S | ≤0.035 | ≤0.035 |
Properties compared
| Property | S55C | S50C |
|---|---|---|
| Tensile strength | ≥650 MPa (normalized, JIS reference) | 610–760 MPa (normalized) |
| 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: S55C · S50C. Substitution decisions for certified parts stay with the design authority.