20CrMo (equivalent to AISI 4118, 20CrMo5, and 20CrMoS4) is a low-alloy chromium-molybdenum steel widely used for components requiring high strength, good toughness, and superior hardenability. It is typically used in gears, shafts, axles, piston rods, and other critical parts in the automotive, power transmission, and machinery sectors.
This steel grade is especially suitable for parts that undergo surface hardening or carburizing to increase wear resistance, while maintaining a tough and ductile core.