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4140 Round Bar

The heat-treated and quenched 4140 round bar delivers unrivaled toughness and durability.

4140 round bar

Get the Strength you Need with 4140 Round Bar

4140 round bar is a high-strength steel alloy that has been useful in a variety of industrial applications for decades. This versatile steel can be machined and welded to meet the needs of many different projects, making it a popular choice for engineers and fabricators.

One of the key features of 4140 steel bar is its exceptional strength. This alloy steel has a high tensile strength and is able to withstand significant amounts of stress and strain without deforming or breaking. This makes it an ideal material for heavy-duty applications such as shafts, gears, and axles.

In addition to its strength, 4140 bar stock is also highly durable and resistant to wear and tear. This makes it an excellent choice for applications that require long-lasting, reliable performance. It can also be heat treated to further enhance its strength and durability, making it an even more versatile material for industrial use.

Another advantage of 4140 steel bar is its versatility. It is practical to use in a variety of different applications, including construction, automotive, and aerospace industries. It is also commonly used in manufacturing machinery, tools, and equipment.

Machinability & Welding

An advantage of 4140 steel is its ability to be hardened with heat treatment. This allows for the material to be customized to the specific needs of the application, providing increased strength, durability, and resistance to wear and tear. The heat treatment process can also improve the material’s toughness, making it better able to withstand high stress and impact.

4140 Steel Applications

4140 bar stock is a versatile, high-strength alloy that can be helpful in a variety of ways. It is a popular choice for heavy-duty applications due to its strength, durability, and ability to withstand high stress and impact. 4140 steel is an alloy that has been used for decades and is well-known for its exceptional mechanical properties.

One of the key features of 4140 steel round bar is its excellent weldability and machinability. This makes it a popular choice for parts that require complex shapes and tight tolerances. The material can be easily machined and formed to meet the specific requirements of a wide range of applications.

The non-heat-treated 4140 steel bar is a popular choice for applications where the part will be exposed to high stress and wear but does not require heat treatment. This material is useful in the construction industry as well as in other heavy industries that require strength and durability.

Some of the most common applications of 4140 steel round bar include shafts, conveyor pins and rolls, motor shafts, pinch bars, hydraulic machinery, nuts, crankshafts, and gears. It is also helpful for parts where welding or brazing are required.



Melting point: 

Tensile strength: 

Hardness, Brinell: 

Yield strength: 

Elongation at break: 

Bulk modulus: 

Shear modulus: 

Elastic modulus: 

Poisson’s ratio: 

0.284 lb/in³


95000 psi


60200 psi


20300 ksi

11600 ksi

27557-30458 ksi


Chemical Properties








96.785 – 97.77

0.380 – 0.430

0.80 – 1.10

0.15 – 0.30

0.15 – 0.25

0.75 – 1.0


Buy 4140 Round Bar

Looking for high-strength, versatile steel for your heavy-duty applications? Look no further than the 4140 bar stock! Made of low-alloy steel, this structural grade steel offers great mechanical properties and excellent weldability. Its unique alloy composition – including chromium, nickel, manganese, silicon, molybdenum, and vanadium – provides ultimate tensile and yield strength.

The 4140 steel round bar is perfect for heavy-duty axles, gears in truck transmissions, and heavy-duty crankshafts for diesel engines. This type of steel is often used in applications that require high strength and toughness, making it a popular choice in many industries.

One of the most common uses of the 4140 steel bar is in the manufacture of gears. The high strength of the 4140 steel allows for the creation of durable gears that can withstand heavy loads and high temperatures.

When you buy a 4140 bar stock, you can rest assured that you are getting a versatile, high-quality product that can be machined at a variety of speeds. While it may not be as tough or hard as some other types of steel, it offers an excellent balance of strength, machinability, and affordability. 

So why wait? Buy a 4140 steel bar today and get the strength you need for your next project!

Do you have questions about this alloy. Just contact a highly skilled personnel from O’Hare Precision Metals. We are dedicated to providing smooth-flow service. Request a quote for round bar stocks now!