Is 42CrMo4 steel alloy steel

42CrMo4 steel is an improved material on the basis of AISI 4140 steel. 42CrMo4 steel has good machinability, high strength and hardenability, good toughness, small deformation during quenching, and high creep strength and rupture strength at high temperature. The executive standard of 42CrMo4 steel plate is EN 10083-3.

Chemical composition of 42CrMo4 steel:
C: 0.38-0.45, Si: ≤ 0.40, Mn: 0.60 -0.90, Cr: 0.90-1.20, Mo: 0.15-0.30
Sulfur S: allowable residual content ≤ 0.035
Phosphorus P: allowable residual content ≤ 0.035
From 42CrMo4 steel chemical composition, it is easy to recognize 42CrMo4 steel as alloy steel.

42CrMo4 steel equivalent grades:
GB 42CrMo, AISI 4140, Japan JIS SCM440, etc.

42CrMo4 steel can be used for forging. Such as big gear for locomotive traction, transmission gear for supercharger, rear axle, connecting rod with great load, etc.