42CrMo steel belongs to ultra-high-strength steel. It has high strength and toughness, and good hardenability. No obvious temper brittleness. After quenching and tempering treatment, it has a higher fatigue limit and resistance to multiple impacts. Good low-temperature impact toughness.


42CrMo steel Worldwide Equivalents

country / regionChinaEUGermanyJapanFranceEnglandUSA
Grade42CrMo42CrMo4 (1.7225)42CrMo4  SCM440H  42CD4708M40 CFS114140 4142
country / regionItalySpainFinlandRussiaInterSweden

Grade42CrMo4  40CrMo4 F1252K10035KHM 38KHM42CrMo42244 

Chemical Composition

0.38 to 0.450.17 to 0.370.50 to 0.80≤ 0.030≤ 0.0300.90 to 1.200.15 to 0.25

Mechanical Properties

  • Yield strength: ≥ 930 MPa
  • Tensile strength: ≥ 1080 MPa
  • Elongation: ≥12%
  • Rate of reduction in area: ≥45%
  • Impact absorbing energy: ≥ 63 J
  • Material Brinell hardness: ≤229 (Annealed or high temperature tempered steel rod)
  • Sample diameter: 25mm

Physical properties of 42CrMo steel

Critical temperature

Critical pointAc1Ac3Ms

Expansion coefficient

Expansion coefficient/℃-111.1×10K12.1×10K12.9×10K13.5×10K13.9×10K14.1×10K

Thermal conductivity

Coefficient of thermal conductivity210000MPa185000MPa175000MPa165000MPa15500oMPa

Heat treatment

First quenching heating temperature: 850 ℃(Cooling – oil)

Tempering heating temperature: 560℃ (Cooling – water, oil)

Features and Application

High strength and hardenability. Good toughness, small deformation during quenching. High creep strength and lasting strength at high temperature.

  • It is used to manufacture forgings that require higher strength and larger quenched and tempered section than 35CrMo steel. Such as large gears for locomotive traction. Supercharger transmission gears, pressure vessel gears. Rear axles, connecting rods and spring clips under heavy load .
  • It can be used for drill pipe joints and fishing tools in oil wells below 2000m.
  • Dies that can be used for bending machines.

Available Size

Round BarDiameter(mm): 6-800mm ,Length: 1000-9000mm or custom size
Plate/Flat/BlockThickness: 6mm-500mm , Width: 20mm-1000mm or custom size
Tolerance±1%,Thickness: +/-0.02mm, Width:+/-2mm