1018 vs 4140 Steel – What’s the Difference

If you are a person who works in the field of manufacturing or construction, you might have come across the terms 1018 and 4140. These are two types of steel with different compositions and properties. Understanding the differences between the two types of steel is essential for selecting the suitable material for your project. This blog post delves deeper into 1018 and 4140 steel and compares their properties, end-use applications, and costs.

What is 1018 Steel?

1018 steel is a low-carbon steel commonly used for applications such as cold-formed components, shafts, gears, and bolts. The steel has good weldability and machinability properties, and the finished product can be heat treated to achieve various desired properties.

What is 4140 Steel?

4140 steel is a high-carbon steel commonly used for applications such as gears, shafts, and connecting rods. The steel has excellent strength and hardness properties, and the finished product can be heat treated to achieve various desired properties.

Difference Between 1018 and 4140

Chemical Properties

1018 steel is a low-carbon steel with a carbon content of 0.18%, while 4140 steel has a higher carbon content of 0.40%. The alloy composition of 4140 steel includes chromium, molybdenum, and manganese, making it more rigid and durable than 1018 steel. The chromium content in 4140 steel provides good corrosion resistance. On the other hand, 1018 steel has a more straightforward composition that makes it easier to weld and work with.

Mechanical Properties

The mechanical properties of steel determine its strength, durability, and other physical characteristics. 1018 steel has a yield strength of 420 MPa (megapascals) and a tensile strength of 520 MPa. It has a moderate to high level of ductility, which means it can deform under pressure without breaking. 4140 steel, on the other hand, has a yield strength of 460 MPa and a tensile strength of 850 MPa, making it significantly more robust than 1018 steel. It also has good wear resistance, making it an ideal material for gears and shafts.

End-Use Applications

The 1018 and 4140 steel properties make them suitable for different end-use applications. 1018 steel is often used in construction, automotive parts, and low-stress applications such as bolts and screws. It is a versatile material that is relatively easy to work with and can be heat-treated to improve strength. On the other hand, 4140 steel is commonly used in the aerospace, oil and gas, and automotive industries, as it has better wear resistance, strength, and fatigue resistance than 1018 steel. It is used in high-stress applications such as crankshafts, gears, and axles.

Applications of 1018 Steel

• Some typical applications for 1018 steel include:
• Cold-formed components such as gears, shafts, and bolts
• Welded structures

Applications of 4140 Steel

Some specific applications for 4140 steel include

• Gears
• Shafts
• Connecting rods

Cost

The cost of steel is an essential factor to consider when selecting a material for your project. 1018 steel is cheaper than 4140 steel, making it a better option for cost-sensitive projects. The cost of both materials can vary depending on the supplier and quantity purchased. However, 4140 steel is more expensive due to its higher alloy composition and durability.

Conclusion

understanding the differences between 1018 and 4140 steel is crucial for selecting the suitable material for your project. 1018 steel is a low-cost, easy-to-work-with option for low-stress applications, while 4140 steel is a durable material with excellent wear resistance, making it ideal for high-stress applications. Knowing the properties, mechanical strength, end-use applications, and cost of each type of steel will help you decide which material to choose for your project.