Cromdane Steel, Inc. distributes quality AISI 4140 alloy steel forged bar and forgings. Our inventory is controlled within our API Q1 and ISO 9001:2015 certified Quality Management Systems requirements and is available for immediate saw, cut and delivery.

We meet stringent customer specifications with short lead times and quick turnarounds.

AISI/SAE 4140 alloy steel is a chrome molybdenum series low alloy steel. AISI 4140 has high strength, hardenability, good toughness, small deformation during quenching, high creep strength and long-lasting strength at temperature. AISI 4140 alloy steel bar has a higher carbon content than AISI 4130 therefor it has greater strength and heat treatment capabilities.

4140 alloy steel forged bar has many uses in the aerospace, oil and gas and automotive industries. It is commonly used in downhole tools.

AISI – SAE 4140 Alloy Steel Composition

4140 steel contains both chromium (Cr) and molybdenum (Mo). The amount of these elements in the alloy varies depending on the grade of 4140 steel being used. For example, Grade AISI 4140 contains 0.38-0.43% Cr and 0.15-0.25% Mo while Grade AISI 4150 contains 0.47-0.53% Cr and 0.20-0.30% Mo. The addition of other elements, such as manganese, can also alter the composition of 4140 steel depending on the grade being used.

AISI – SAE 4140 Alloy Steel Chemical Properties

SAE 4140 steel is a chromium-molybdenum alloy beloved by many metalworkers because of its versatility and malleability. Due to its impressive chemical properties, it has been used in applications ranging from shipbuilding to the manufacture of tools. 4140 Steel has excellent strength, toughness, and hardenability values, especially when tempering and quenching are employed for further processing. Additionally, it is highly corrosion-resistant and has a large amount of wear resistance as well. This makes it ideal for uses like shafts, gears, bolts, and other parts subject to mechanical stress. As a result of all these qualities, 4140 Steel remains one of the most popular materials for metalworking today – and it doesn’t look like that popularity will be waning anytime soon!

AISI – SAE 4140 Alloy Steel Physical Properties

The chemical and physical properties vary depending on the grade being used; however, some common characteristics are high strength (up to 1600MPa), high wear resistance (due to its high abrasion resistance), good ductility and toughness (due to its low carbon content), high fatigue strength (due to its quenching process), good creep strength (at elevated temperatures), good corrosion resistance (due to its chromium content) and good weldability (due to its low carbon content).

AISI – SAE 4140 Alloy Steel Mechanical Properties

AISI – SAE 4140 Alloy Steel Thermal Properties

AISI – SAE 4140 Alloy Steel Equivalent

AISI – SAE 4140 Alloy Steel Uses

Due to its versatility, 4140 steel has many uses across various industries, including automotive components such as gears shafts, axles, pistons, and valves ; construction materials such as bolts, nuts, screws; tools such as chisels, punches, taps etc.; sporting goods such as golf clubs; agricultural equipment such as plows; oil rigs etc.