Hardening surface while keeping tough core
| Method | Case Depth | Hardness | Temp |
|---|---|---|---|
| Carburizing (Gas) | 0.5-2mm | 58-64 HRC | 900-950C |
| Nitriding (Gas/Ion) | 0.1-0.5mm | 60-70 HRC | 500-550C |
| Carbonitriding | 0.3-0.8mm | 58-64 HRC | 830-870C |
| Induction Hardening | 1-5mm | 55-62 HRC | Localized |