4140 vs 4130 Steel: The Right Steel for Your Project

4140 vs 4130 Steel: The Right Steel for Your Project

Two steel alloys commonly used in metalworking are 4140 and 4130 steels. Both are high-strength, low-alloy steels that are very tough and resistant to wear. However, they do not have the same composition, properties, and uses.

Therefore, this study will examine the differences between 4140 and 4130 steels. This study will also discuss their properties, how they are used, and important things to consider when choosing the right steel grade. Let’s read on.

Table of Contents

What Is 4140 Alloy Steel?

Containing chromium, phosphorus, sulfur, molybdenum, and manganese, 4140 steel is a low alloy that can be used for a variety of applications. Because it contains a certain amount of carbon, it can be hardened and heated to obtain a variety of strengths.

In addition, 4140 steel is very tough, resistant to wear, and has high-stress strength. As a result, it is a popular choice where high-performance materials are required. Axles, shafts, gears, and hydraulic components all fall into this category.

Why Do I Need to Treat the Surface of My Metal Stampings?

Making precision metal stampings is very important. Therefore, you need to plan to choose a surface treatment method. After this treatment, the metal will last longer and thus be more useful in other areas. It can also help your business grow if you know you are selling good stamped parts.

In addition to the reasons mentioned above, there are many other benefits to having the following treatments applied to metal surfaces:

  • Prevents corrosion. Metal that does not rust is a good sign of a strong material that can be used in any situation. Stamped parts must be highly resistant to galvanic, pitting, and crevice rust.
  • Improved Appearance. Finishing the surface of the metal can be decorative by making it look better and more balanced. It can be shiny or matte, embossed or plain.
  • Improves durability. As we have already said, it makes the metal last longer. It makes the surface of the part harder, which is important when making stampings for medical tools, construction materials, and automotive parts.
  • It improves the metal’s electrical properties, resistance to fading, and chemical resistance. All of these benefits increase the value of the metal.

Properties of 4140 Steel

The unique properties of 4140 steel come from the way the metal works together within itself, making 4140 steel suitable for many CNC steel processing tasks and sheet metal fabrication. Here are some of the key characteristics of 4140 steel:

High tensile and fatigue strength: 4140 steel has high tensile and fatigue strength, making it suitable for highly stressed parts such as crankshafts, gears, and axles.

Excellent toughness and hardness: 4140 steel is heat-treated to a very high hardness of 58 HRC, which makes it ideal for a wide range of applications. In addition, 4140 steel is tough enough to withstand heavy loads without breaking, as it does not crack or break easily on impact.

Good corrosion resistance: Rusting agents have a hard time destroying 4140 steel, especially when compared to other alloy steels. Therefore, it is a good choice for parts that are often subjected to harsh conditions. Note, however, that the corrosion resistance of stainless steel is higher than that of 4140 steel.

Machinability: 4140 steel is not difficult to machine, especially after heating. However, once it hardens, it is difficult to machine.

What is 4130 Alloy Steel?

4130 steel is also a low alloy steel. This steel has a relatively low carbon content. It also contains chromium, sulfur, silicon, molybdenum, manganese, and phosphorus. By combining these elements, 4130 steel acquires its unique qualities. Such as high strength, toughness, wear resistance, and corrosion resistance. Because of this, it is used in the manufacture of many airplanes and other highly loaded components.

Properties of 4130 Steel

Because of its properties, 4130 steel is used in a variety of industrial processes. Here are some of the most important 4130 steel properties:

Hardness and tensile strength: Like 4140 steel, 4130 steel is very hard and has high tensile strength, so it can be used in high-stress applications. Compared to mild steel, 4130 steel has a higher weight-to-strength ratio. Because of this, it is well suited for fabrication work where weight is critical.

Elasticity: 4130 steel is highly elastic, with a yield strength of 460 MPa. This means that the material can withstand a great deal of stress and still return to its original shape.

Ductility: 4130 steel is very ductile, especially after annealing. As a result, lines can be easily made from this steel.

Corrosion and temperature resistance: 4130 steel is also very resistant to corrosion and high temperatures without losing its shape or structure.

Difference Between 4130 Steel and 4140 Steel

There are several types of alloy steels, each with its own properties and characteristics and therefore suitable for specific applications. 4140 steel and 4130 steel are two types of steel that are often compared.

These two types of steel are strong and tough and are low-alloy steels that are used in many applications. However, these two steels are completely different in some important ways. Here are some of these differences:


The main difference between 4140 and 4130 steels is their chemical composition, just like the main difference between 1018 and 4140 steels. The chemical composition of the two steels is listed below.

The chemical composition of 4140 steel is as follows:

  • Carbon: 0.38%-0.43
  • Chromium: 0.8%-1.1%
  • Manganese: 0.75%-1.0
  • Phosphorus: 0.035% (max)
  • Sulfur: 0.040% (max)
  • Silicon: 0.15%-0.35% (max)
  • Molybdenum: 0.15%-0.25

4130 steel consists of the following chemical composition:

  • Carbon: 0.28%-0.33
  • Chromium: 0.8%-1.1%
  • Manganese: 0.40%-0.60
  • Phosphorus: 0.035% (max)
  • Sulfur: 0.040% (max)
  • Silicon: 0.15%-0.35% (max)
  • Molybdenum: 0.15%-0.25

As can be seen from the chemical composition above, 4140 steel has a higher carbon and manganese content than 4130 steel. However, both steels have approximately the same amount of chromium, sulfur, s

Heat Treatment

Both 4140 and 4130 steels can be heat treated to improve their properties. However, different heat treatments are required to obtain the desired properties. To make 4140 steel very strong and tough, it needs to be quenched and tempered.

For quenching, 4140 steel is heated to temperatures between 1600°F and 1650°F. It is then cooled in oil or water to achieve a Rockwell hardness of 40-45 HRC. After the steel is hardened, it is tempered at 500°F to 600°F to make it tougher while retaining its hardness.

On the other hand, 4130 steel is usually normalized and tempered to obtain the same qualities. 4130 steel is heated to a temperature of approximately 1600°F to 1700°F during the straightening process and then cooled in air. This helps to increase its strength and toughness.

Mechanical Properties

The mechanical properties of 4140 and 4130 steels vary depending on the heating method and application. Here is a look at how the mechanical properties of these steels differ:

Toughness and Strength

4140 steel is suitable for highly stressed parts because its tensile and yield strengths are superior to those of 4130 steel. 4140 steel has a tensile strength of between 655 and 979 MPa, while its yield strength is around 415 MPa. After hardening and tempering, 4140 steel has a hardness of 28 to 32 HRC. However, when annealed, 4140 steel has a lower hardness of about 17 HRC.

On the other hand, 4130 steel is tougher and more flexible than 4140 steel, but its tensile and yield strengths are lower. 4130 steel has a yield strength of about 460 MPa and a tensile strength in the range of 560 to 725 MPa. 4130 steel has a hardness in the range of 15 to 23 HRC.


Due to its lower carbon content, 4130 steel is easier to machine than 4140 steel. For the most part, experts use standard techniques such as drilling, milling, and turning to machine 4130 steel without fear of scorching or damaging the workpiece. When working with 4140 steel, on the other hand, more care must be taken to avoid cracking.


One of the advantages of 4130 steel is that it can be welded. Due to its lower carbon content, it is easier to weld than 4140 steel. You can weld 4130 using any standard method, such as gas tungsten arc welding (GTAW) or gas metal arc welding (GMAW).

On the other hand, 4140 steel needs to be heated and then treated differently after welding to ensure a strong, durable, defect-free weld.


Both 4140 and 4130 steels are widely used for various tasks in many fields. However, because 4140 steel is slightly stronger than 4130 steel, it has a longer service life. Therefore, it is often used in applications where it is required to withstand harsher conditions or higher stress levels.

Thermal Spraying

By spraying molten and heated metal, this finish makes it easier to prevent scratches, flaking, and cracking on the surface of metal parts. It can help large metal stampings bond together.

How Do You Choose Between 4130 and 4140 Steel?

4140 and 4130 steels are both very strong and tough, but they have different inherent properties. Therefore, you need to understand the differences between these two types of steel in order to choose the right one for your job. That’s what 4140 vs. 4130 steel is all about. Here are some suggestions to help you make the right choice:

Compare the Chemical Composition of the Two Steels

The amount of carbon, manganese, chromium, silicon, sulfur, and molybdenum in 4140 steel is different from that in 4130 steel. You can compare the chemical composition of the two steels to find the one that best suits your needs.

Checking the Mechanical Properties of both Steels

For applications requiring high strength and hardness, 4140 steel may be a better choice. 4140 steel has a higher carbon and manganese content and can be hardened and tempered. This makes it ideal for parts that are subjected to high levels of stress.

Additionally, if your product requires lower strength and higher ductility, 4130 steel is also a better choice. Therefore, check the tensile strength, yield strength, and hardness of both steels to see which one is better suited for your needs.

Determine Machinability Requirements

If your application requires easy machinability, 4130 steel is a good choice. This is because it has a lower shear stress strength, which means it removes chips faster and requires less cutting force when machining complex shapes.

However, if your application requires very strong and difficult-to-machine parts, use 4140 steel. 4140 steel is more difficult for machines to machine because it takes longer to remove chips and requires more force. In addition, you may want to make sure that the steel you are using can be laser engraved before making your selection.

Make Sure You Understand the Rules of Heat Treatment

different types of heating. Therefore, if the job requires a certain type of heat treatment, it may affect your choice of steel.

Therefore, you need to know which heat treatment is required for your application. Then compare its properties with those of the two steels and make your choice.

Consider Price

The price of 4130 and 4140 steels can change for a number of reasons. Some of these reasons include the supplier, the amount of steel required, the specific grade of steel, and the unique needs of the application.

Therefore, check the price of both types of steel and choose the one that best meets your needs. 4140 steel is usually a bit more expensive than 4130 steel because it is stronger and harder.

Applications for 4140 and 4130 Steel

Because of their metallic properties, 4140 and 4130 steels are used in many industries. Here are some of them:

Automotive industry: Automotive industry workers use 4140 steel to manufacture important parts such as connecting rods, crankshafts, and gears. Because 4130 steel is so strong and resistant to wear, it is also used to make racing car frames, roll cages, and suspension components.

Construction: 4140 steel is also used in the construction industry for building and bridge components that need to be strong and durable.

Aerospace: Aerospace professionals use 4140 and 4130 steel to manufacture aircraft components. Such as landing gear, wings, engine parts, and other structural components.

Structural tubing: 4130 steel is used to make bicycle frames, motorcycle frames, sports equipment, and other structural tubing because it has a high strength-to-weight ratio and is easy to weld.

Use steel as a customized processing design of the basic material mechanical parts

Yonglihao Machinery Provides High-quality Service for Processing 4140 and 4130 Steel

Steel processing is probably one of the most popular manufacturing methods in many areas today. Many different companies use different grades of steel for different types of fabrication. However, some people have trouble choosing the right grade of steel for their projects because they have different properties.

By choosing Yonglihao Machinery, you can hire the best professionals to handle every step of your steel processing job. As part of our metal fabrication services, we also offer high-quality surface treatments to give your steel-fabricated parts the best possible finish. Contact our customer service today to learn more and you will receive a free quote soon.


4140 and 4130 steels are both low alloy steels, and they both offer high strength, toughness, and corrosion resistance. Because of this, they are still used in the manufacturing processes of many companies today.

While 4140 and 4130 steels are related in some ways, they are also very different in other important ways. The best way to choose the right steel for your manufacturing project is to understand the variations and similarities between these grades.


In terms of which steel is better, it depends on the application and the needs of the application. At the end of the day, it’s important to talk to a materials engineer or part manufacturer to find out which steel is best suited for a particular job.

The nickel, chromium, and molybdenum in 4140 steel improve passivation properties and make it more resistant to corrosion. As a result, this steel can still be used to manufacture items for use in harsh, corrosive environments.

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