51CrMoV4 steel is a kind of spring steel , as spring steel for quenching in oil. The strength and hardenability of 51CrMoV4 steel is strengthened not only by chromium and vanadium – as in the case of 51CrV4 / AISI 6150, but also by molybdenum. Molybdenum strengthens the solution during heat treatment, while chromium and vanadium form carbides that improve the hardness of the material during tempering.
51CrMoV4 equivalent steel grades:
| UNI | DIN | AFNOR | SAE/AISI | EN |
| 51CrMoV4 | 1.7701 | 51CDV4 | 4150 | 52CrMoV4/1.7701 |
51CrMoV4 properties:
Treated for cold shearability +S: ≤ 280 HB
Soft annealed +A: ≤248 HB
Spheroidized annealed – GKZ (+AC):≤225 HB
Core hardness after quenching: ≥54 HRC
