4130 Alloy Steel

4130 is a chromium-molybdenum low-alloy steel offering a good combination of strength, toughness, weldability, and heat-treatability. Compared with conventional carbon steels, 4130 provides higher mechanical strength while maintaining good toughness, making it suitable for aerospace, automotive, energy, and high-strength mechanical structures.

Appearance & Properties

Color: Silver-gray to dark gray

Density: Approx. 7.85 g/cm³

Tensile Strength: Approx. 560–700 MPa (varies with annealed, normalized, and other conditions)

Corrosion Resistance: Poor

Machinability: Good

Weldability: Good

Toughness: Good

Magnetism: Magnetic

Heat Treatment: Normalizing, hardening, tempering, etc.

Surface Finishes: Zinc plating, nickel plating, black oxide, phosphating, painting, powder coating, etc.

Typical Applications

4130 Alloy Steel is widely used in aerospace, automotive and motorsports, oil and gas, industrial machinery, energy equipment, and engineering machinery.

Typical parts include aerospace structures, drive shafts, gears, connectors, high-strength brackets, flanges, sleeves, fasteners, and various load-bearing precision CNC components.

Advantages

• Good combination of strength and toughness

• Good heat-treatment capability

• Good CNC machinability

• Better weldability than many higher-strength alloy steels

• Suitable for medium-to-high load mechanical structures

Limitations

• Poor corrosion resistance and usually requires surface protection

• Machining becomes more difficult after heat treatment

• Lower strength than some higher-strength alloys such as 4140 and 4340

• Final mechanical properties depend strongly on heat-treatment condition