C70 is an affordable steel, often one of the first steels used by beginners and also highly appreciated by experienced makers for certain types of knives due to its physical and mechanical properties.
Chemical Composition
| C | Si | Mn | Cr | Mo |
| 0.70% | 0.25% | 0.71% | 0.03% | 0.02% |
Forging: Heat to 1150° C. Do not forge below 815° C.
Normalizing Heat to 855° C. Cool in still air.
Annealing: Heat to 800° C. Furnace cool to 650° C at a rate not exceeding 28° C per hour.
Hardening: 850° C. Hold for 1.5 minutes per mm of thickness, quench in Durixol V35 oil 60° C.
Tempering: Hardness when quenched is approximately 65 HRC. Tempering time 40 minutes x 2.
| Temperature: | Hardness HRC |
| 150°C | 63 |
| 180°C | 62 |
| 200°C | 61.5 |
| 230°C | 60 |
| 260°C | 59 |
| 290°C | 56.5 |
| 320°C | 56 |
| 340°C | 55 |