4130 vs 4140 Steel Comparison

The following is a comparison of 4130 grade steel and 4140 grade steel. This information may be useful for machining purposes and as a resource for purchasing 4130 and 4140 steel.

Chemical Properties

The chemical properties of 4130 and 4140 steel are similar aside from differences in Carbon and Manganese concentrations.

  4130 4140
Carbon, C 0.30% 0.40%
Manganese, Mn 0.40-0.60% 0.75-1.00%
Chromium, Cr 0.80-1.10% 0.80-1.10%
Molybdenum, Mo 0.15-0.25% 0.15-0.25%

Mechanical Properties

 The following are the mechnical properties for both normalized and annealed 4130 and 4140 steel.

Normalized

  4130 4140
Tensile Strength 97,000 psi 148,000 psi
Yield Strength 63,000 psi 95,000 psi
Elongation (2") 25.5% 17.7%
Reduction in Area 59.5% 46.8%
Brinell Hardness 197 302

Annealed

  4130 4140
Tensile Strength 81,300 psi 95,000 psi
Yield Strength 52,300 psi 60,500 psi
Elongation (2") 28.2% 25.7%
Reduction in Area 55.6% 56.9%
Brinell Hardness 156 197

The relative machinability Rating percentage based on SAE1212 as 100% is the following for cold drawn 4130 and cold drawn 4140 steel

  • 4130 - 70%
  • 4140 - 65%