GCr15SiMn
Data verifiedGCr15SiMn 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.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.95–1.05 |
| Si | 0.40–0.65 |
| Mn | 0.90–1.20 |
| P | ≤0.025 |
| S | ≤0.025 |
| Cr | 1.30–1.60 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Spheroidize annealed |
| Hardness (hardened) | 61–65 HRC |
| Density | 7.85 g/cm³ |
| Hardenability | Well above GCr15 — for large rings and rollers |
Heat treatment
Spheroidize anneal per GB/T 18254; harden 820–850 °C oil; temper 150–180 °C.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.3520 (100CrMnSi6-4, near) |
| aisi | 52100 family (near) |
| jis | SUJ4 (near) |
| gb | GCr15SiMn (GB/T 18254) |
Compare side by side: GCr15SiMn vs GCr15 · GCr15SiMn vs 52100 · GCr15SiMn vs 100Cr6
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Large bearing rings and rolling elements, wind-energy bearings, cold rolls, mill rolls.
Processing: As GCr15/52100; specify the GB/T 18254 quality level for fatigue-critical parts.
FAQ
- GCr15 or GCr15SiMn?
- Same carbon and chromium; the SiMn version is chosen when section size defeats GCr15 hardenability — large rings, thick rollers and wind-turbine bearings.
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Ask for a quotationVisit NasteelSource: GB/T 18254 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.