65Mn steel is a Chinese GB standard spring steel grade, Manganese (Mn) improves hardenability, so the strength, hardness, elasticity and hardenability are higher than that of 65# steel, but it has overheat sensitivity and temper brittleness. Water quenching tends to form cracks. The annealed state has good machinability, low cold deformation plasticity, and poor weldability.
65Mn high carbon steel is mainly used in the manufacture of various small-section flat springs, round springs, clockwork, etc. It can also be used to manufacture spring rings, valve springs, shock absorbers, clutch reeds and brake springs.