SCM440 under JIS Standard. 

42CrMo4 under DIN standard

708M40/708A42/709M40 under BS standard

42CrMo under GB Standard

Grade	Chemical composition %
	C	Si	Mn	P	S	Cr	Ni	Mo	Cu
4140	0.38~0.45	0.17~0.37	0.50~0.80	≤0.035	≤0.035	0.9~1.2	≤0.3	0.15~0.25	≤0.3
	Mechanical properties
	Tensile Strength (Mpa)		Yield Strength (Mpa)		Elongation in 2 in. %		Akv (J)	Hardness
	≧1080		≧930		≧12		≧63	≤217HB

Characteristic:  4140 steel tube has good processing and anti-fatigue performance, which belongs medium hardenable steel. 4140 heat treatment has good strength and good comprehensive mechanical properties, high yield strength. The highest working temperature is 427 ℃ . It has good toughness, quenching deformation high creep strength and lasting strength under high temperature. 

Application:Manufacturing more than 35CrMo steel strength and higher quality forging section, such as locomotive traction with a large gear, supercharger transmission gear and rear axle. It can be also used well drilling pipe joints and salvage tools, and can be also used for bending machines and other molds.