GCr15SiMn vs 52100
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.
GCr15SiMn
Alloy & Engineering Steel
GCr15SiMn is the high-hardenability bearing steel of GB/T 18254: extra silicon and manganese over GCr15 let large bearing rings and rollers through-harden, where plain GCr15 would stay soft at the core.
Standards: DIN 1.3520 (100CrMnSi6-4, near) · AISI 52100 family (near) · JIS SUJ4 (near) · GB GCr15SiMn (GB/T 18254)
52100
Alloy & Engineering Steel
52100 is the world-standard through-hardening bearing steel (ASTM A295): about 1% carbon and 1.5% chromium, hardened to 62–66 HRC for rolling contact fatigue resistance. The JIS name is SUJ2 and the EN name 100Cr6 — all describe the same grade family.
Standards: DIN 1.3505 (100Cr6) · AISI 52100 · JIS SUJ2 · GB GCr15
Chemical composition compared (%)
| Element | GCr15SiMn | 52100 |
|---|---|---|
| C | 0.95–1.05 | 0.98–1.10 |
| Si | 0.40–0.65 | 0.15–0.35 |
| Mn | 0.90–1.20 | 0.25–0.45 |
| P | ≤0.025 | ≤0.025 |
| S | ≤0.025 | ≤0.025 |
| Cr | 1.30–1.60 | 1.30–1.60 |
Properties compared
| Property | GCr15SiMn | 52100 |
|---|---|---|
| Delivery condition | Spheroidize annealed | Spheroidize annealed (≈180–210 HB) |
| Hardness (hardened) | 61–65 HRC | 62–66 HRC |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Hardenability | Well above GCr15 — for large rings and rollers | — |
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: GCr15SiMn · 52100. Substitution decisions for certified parts stay with the design authority.