Description

4140 is a low-alloy steel known for its high strength, toughness, and excellent wear resistance. It is commonly used in a variety of industrial applications that require strong and durable components.

Applications

4140 is widely used in machinery parts, axles, shafts, gears, bolts, studs, and other components where high strength, toughness, and wear resistance are essential.

Blacksmith Applications

4140 is commonly used in blacksmithing applications such as forging tools, hammers, punches, and other implements where strength, toughness, and wear resistance are crucial for withstanding repetitive impact and heavy use.

4140 Forging Temperature

Forging should be done between 1750°F - 2100°F (954°C - 1149°C), followed by slow cooling in a furnace or insulating material to reduce internal stresses.

4140 Heat Treatment

4140 Annealing Temperature

Annealing is typically performed at 1550°F - 1600°F (843°C - 871°C) for a sufficient amount of time, followed by slow cooling in the furnace to relieve internal stresses and improve machinability.

4140 Normalizing Temperature

Normalizing can be carried out at 1600°F to 1700°F (871°C to 927°C) for a proper soak time, followed by air cooling to enhance the material's mechanical properties.

4140 Hardening Temperature

Hardening is achieved by heating the steel to 1550°F to 1650°F (843°C to 899°C) and then quenching in oil or water to obtain the desired hardness and strength.

4140 Tempering Temperature

Tempering should be performed between 400°F to 1200°F (204°C to 649°C) depending on the desired hardness and toughness. Higher temperatures will result in lower hardness but increased toughness.

Machinability

4140 has a machinability rating of 60 compared to 1% carbon steel, indicating good machinability with appropriate cutting tools and techniques.

Weldability

4140 has moderate weldability. Preheating and post-weld heat treatment are often required to minimize the risk of cracking and achieve desired properties. However, welding can significantly reduce the material's strength and toughness.