GCr15SiMn vs GCr15
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)
GCr15
Alloy & Engineering Steel
GCr15 is China’s standard bearing steel (GB/T 18254), the domestic designation of the 52100/100Cr6/SUJ2 family. Chinese mills produce it in very large tonnage for bearing rings, rolling elements and precision parts.
Standards: DIN 1.3505 (100Cr6) · AISI 52100 · JIS SUJ2 · GB GCr15 (GB/T 18254)
Chemical composition compared (%)
| Element | GCr15SiMn | GCr15 |
|---|---|---|
| C | 0.95–1.05 | 0.95–1.05 |
| 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 | 1.40–1.65 |
Properties compared
| Property | GCr15SiMn | GCr15 |
|---|---|---|
| Delivery condition | Spheroidize annealed | Spheroidize annealed |
| Hardness (hardened) | 61–65 HRC | 61–65 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 · GCr15. Substitution decisions for certified parts stay with the design authority.