4140 steel, is a kind of alloy structural steel, its strength, high hardenability, good toughness, quenching deformation is small.

Chemical composition:

Carbon C: 0.33 ~ 0.48

Silicon Si: 0.15 ~ 0.35

Manganese Mn: 0.75 ~ 1.00

S: sulfur 0.030 or less

P P: 0.030 or less

Cr: 0.80 ~ 1.10

Mo: 0.15 ~ 0.25

Performance characteristics;

Strength, high hardenability and good toughness, quenching deformation of small, high temperature creep rupture strength and high from time to tome, for the manufacture requirements higher than 35 grmo steel strength and conditioning section more large forgings, such as locomotive traction with the big gear, supercharger drive gear, rear axle, load of connecting rod and a spring clip, also can be used in the 2000 meters deep well of oil drill pipe joint and the fishing tool and so on.
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