4140 alloy steel

High tensile strength and toughness
Excellent fatigue and impact resistance
Superior hardenability through heat treatment
Good wear resistance under heavy loads
Reliable machinability and processing performance
Suitable for high-stress mechanical applications

42CrMo4/ 1.7225 /4140 alloy steel

42CrMo4 Alloy Steelis a high-strength chromium-molybdenum alloy steel widely used in demanding engineering and mechanical applications. Also known as 1.7225 steel, 42CrMo4 steel is recognized for its excellent combination of strength, toughness, and fatigue resistance.42CrMo4 alloy steel bar is commonly supplied in the form of 42CrMo4 round bar, forged bar, and machined components. Due to its excellent hardenability and heat treatment response, 42CrMo4 steel is widely used in automotive, oil & gas, machinery, and heavy engineering industries.

Compared with standard carbon steels, 42CrMo4 alloy steel provides significantly higher tensile strength, improved wear resistance, and better performance under high stress conditions. This makes 42CrMo4 steel round bar a preferred material for shafts, gears, bolts, and structural components.

Key Features

High tensile strength and toughness
Excellent fatigue and impact resistance
Superior hardenability through heat treatment
Good wear resistance under heavy loads
Reliable machinability and processing performance
Suitable for high-stress mechanical applications

Chemical Composition (Typical)

Element	Composition (%)
Carbon (C)	0.38 – 0.45
Chromium (Cr)	0.90 – 1.20
Molybdenum (Mo)	0.15 – 0.30
Manganese (Mn)	0.50 – 0.80
Silicon (Si)	0.15 – 0.40
Phosphorus (P)	≤ 0.025
Sulfur (S)	≤ 0.035
Iron (Fe)	Balance

Mechanical Properties

Property	Typical Value
Tensile Strength	900–1100 MPa
Yield Strength	≥ 700 MPa
Elongation	≥ 12%
Hardness	28–32 HRC (quenched & tempered)
Density	7.85 g/cm³
Heat Treatment	Quenched & Tempered