20MnCr5 is a low-alloy, case-hardening steel known for its high core tensile strength (1000-1300 N/mm²) and good wear resistance. It's commonly used in mechanical components like gears, shafts, and other parts requiring a hard, wear-resistant surface and a tough core. The steel's case-hardening properties allow it to achieve high surface hardness after heat treatment, while maintaining good ductility and fatigue strength due to its small grain size.