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4140 Bar

Need a reliable alloy steel? Look no further than 4140 bar stock - the metal of choice for high-performance industries.

4140 Steel Bar Stock - The Perfect Alloy for High-Stress Situations.

From machinery to automobiles, 4140 bar stock and 4142 alloy steel are the steels of choice for demanding applications.

4140 is a Chromium-Molybdenum alloy steel that is one of the most popular among the alloy steels. Thus, the primary alloying elements are chromium and molybdenum. As a result, 4140 is helpful in applications requiring high wear resistance and temperatures. 

Meanwhile, 4142 alloy steel is useful in various industrial applications, including tools and other types of equipment. After heat treatment, it is a medium carbon chromium-molybdenum alloy steel with high strength and toughness.  

What is 4142 Alloy Steel?

4142 alloy steel is a type of alloy steel that contains nickel, chromium, molybdenum, and columbium as its primary alloying elements. It is known for its high strength, toughness, and excellent fatigue and impact resistance properties. 
It also has good corrosion resistance and can be easily machined and welded. 4142 alloy steel is commonly used in the production of automobiles, construction equipment, and other machinery.

Machinability and other Processes

4140 bar stock and 4142 alloy steel are both popular choices for use in the manufacturing industry due to their high strength and toughness after heat treatment. One important factor to consider when working with these materials is their machinability, or the ease with which they can be machined into different shapes and sizes.

4140 bar stock has a machinability rating of 66%, which is considered excellent. This means that it can be machined with relative ease using standard machining practices. However, the presence of molybdenum in the material can contribute to the uniformity of hardness and high strength, which can make it more difficult to machine compared to other types of steel.

On the other hand, 4142 alloy steel is known for its excellent machinability. It is a low carbon, high nickel, and high chromium steel that has good formability and weldability in annealed conditions. When compared to other similar materials like 4130 or 4140, it has a lower carbon content which makes it easier to machine. This also means that 4142 steel doesn’t require as much heat during welding because of its lower melting temperature.

It’s worth noting that the machinability of steel increases as it is hardened and tempered. This means that the heat treatment process can improve the machinability of both 4140 and 4142, although it can also make the material more difficult to machine in some cases.


Axles, shafts, tools bodies, tie rods, stubs, couplings, reamers, gears, racks are the common applications of 4140/4142 Alloys.

4140 round bar stock



Poisson’s ratio 

Elastic modulus

Bulk modulus 

Shear modulus 

0.284 lb/in³  


27557-30458 ksi  

20300 ksi   

11600 ksi

Chemical Properties









0.40-0.45 0.380 – 0.430

0.80-1.10 0.80 – 1.10

0.75-1.10 0.75 – 1.0

0.15-0.25 0.15 – 0.25

 0.035 0.035

0.15-0.30 0.15 – 0.30

0.040 0.040

96.725 Balance

Comparison of 4140 Bar Stock and 4142 Steel: Understanding the Differences

4140 bar stock and 4142 steel are both types of steel that have similar properties but some key differences.

4140 bar stock is a type of steel that is useful in the manufacturing industry to make bars for machinery, automobiles, and other high-stress applications. It is an alloy of chrome, nickel, and molybdenum, which gives it a high tensile strength and resistance to corrosion. Additionally, it is heat-treated and quenched to remove all impurities from the metal, making it rust-resistant and easy to machine.

On the other hand, 4142 steel is also helpful in the production of machinery, automobiles, and construction equipment. It is an alloy steel containing nickel, chromium, molybdenum, and columbium, and has good corrosion resistance, strength, and toughness properties. However, 4142 steel has a lower carbon content than 4140 bar stock, making it easier to machine and weld due to its lower melting temperature.

Overall, both types of steel have their own unique advantages depending on the application. Choosing the right type of steel is important based on your project’s specific needs.

O’Hare’s 4140 Bar and 4140 Steel for Sale

O’Hare Precision Metals is a reputable company that specializes in providing high-quality 4140 and 4142 steel bar stock. As a leading supplier in the United States, we offer a wide range of metals and metal products that are guaranteed to meet your high demands.

Want to know more about these alloys? Just contact our highly skilled personnel in O’Hare Precision Metals. They are dedicated to providing smooth-flow service. Request a quote for bar stocks now!