Description

4140 is a versatile low-alloy steel known for its high tensile strength, toughness, and good fatigue resistance. It is commonly used in various industrial applications.

Applications

4140 is widely used in applications such as gears, shafts, axles, bolts, studs, and machinery components where high strength and good wear resistance are required.

Blacksmith Applications

4140 Forging Temperature

Forging should be done between 2100°F to 2300°F (1149°C to 1260°C), followed by slow cooling in a furnace or insulating material.

4140 Heat Treatment

4140 Annealing Temperature

Annealing is typically performed at 1550°F to 1650°F (843°C to 899°C) for a sufficient amount of time, followed by slow cooling in the furnace to relieve internal stresses.

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.

4140 Hardening Temperature

Hardening is achieved by heating the steel to 1575°F to 1625°F (857°C to 885°C) and then quenching in oil or water, depending on the desired hardness.

4140 Tempering Temperature

Tempering should be performed between 400°F to 1200°F (204°C to 649°C) to achieve the desired hardness and toughness.

Machinability

4140 has a machinability rating of 60, indicating good machinability with appropriate cutting tools and techniques. It can be machined in the annealed or normalized condition.

Weldability

4140 has good weldability with proper preheating and post-weld heat treatment. It is recommended to use low hydrogen welding methods and suitable filler materials.