These are steels and materials with the best combination of mechanical resistance and tenacity.

The use of these steels is directed, almost mainly at mechanical parts for which good properties of shock and vibration resistance are required (toothed wheels, rods, pins, shafts, levers).

There are different types on sale, containing carbon only (c45) or with alloy elements in larger or smaller amounts (Ni, Cr, Mo, Mn); generally, the percentage of carbon will vary from 0.21% to 0.60%.