Steel vs Iron: Understanding the Differences in CNC Machining(thermosets vs thermoplastics Michelle)

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When it comes to manufacturing and fabrication, CNC machining plays a pivotal role. This advanced technique offers precise control and efficiency for producing various products using a computer numerical control (CNC) system. While there are numerous materials used in CNC machining, two prominent ones often compared are steel and iron. In this article, we will delve into their characteristics, compare their advantages and disadvantages, and explore their applications in CNC machining.

Distinguishing Steel and Iron:

Steel is an alloy composed mainly of iron with varying amounts of carbon and other elements such as manganese, silicon, and chromium. Its unique composition gives it superior strength, ductility, and corrosion resistance when appropriately engineered. Additionally, steel can be easily machined, making it a popular choice in many industries ranging from automotive to construction.

Pure iron has limited use due to its low strength and high brittleness. However, iron alloys, commonly known as cast iron, are widely utilized for their exceptional wear resistance and excellent thermal conductivity. Cast iron consists of iron combined with varying quantities of carbon and silicon, which enhance its properties and make it suitable for specific applications, such as engine blocks or machinery parts.

Comparing Steel and Iron in CNC Machining:

1. Strength and Hardness:
Steel possesses higher tensile strength than iron due to its carbon content, making it ideal for carrying heavy loads and resisting deformation. The hardness of steel allows it to withstand repeated impacts and high-speed cutting processes during CNC machining.
On the other hand, while iron has lower tensile strength, cast iron demonstrates excellent compressive strength. It is used in applications requiring durability against crushing forces.

2. Machinability:
Both steel and iron have good machinability, but they require different approaches during CNC machining. Steel's malleability makes it relatively easy to cut, form, and shape using cutting tools. High-speed steel (HSS) or carbide-based tooling is typically used for machining carbon steels, while stainless steels require specialty tools due to their higher hardness.
Cast iron, however, poses some challenges in CNC machining due to its abrasive nature and brittleness. Proper selection of cutting speed, feed rate, and tool materials, such as polycrystalline cubic boron nitride (PCBN), can help overcome these difficulties.

3. Corrosion Resistance:
One significant advantage of steel over iron is its excellent corrosion resistance. The presence of alloying elements like chromium forms a protective layer that prevents rust formation on the surface. This makes steel particularly useful in corrosive environments where iron would deteriorate quickly.

4. Applications:
Steel's versatility allows it to be used in a wide range of applications, including automotive components, machinery parts, construction, and consumer goods. Its strength, durability, and ductility enable engineers to create complex shapes without compromising structural integrity through CNC machining.
Iron alloys find application where impact resistance, vibration dampening, and wear resistance are critical. Engine blocks, brake discs, machine bases, and gears are common uses of cast iron in industries requiring reliable performance under severe conditions.


In CNC machining, both steel and iron have their unique properties and advantages. Steel, with its superior strength, machinability, and corrosion resistance, offers immense flexibility in various applications. On the other hand, iron alloys bring exceptional hardness, compressive strength, and wear resistance to specific industrial requirements.
Understanding the differences between these materials allows manufacturers to select the most suitable one for their CNC machining needs. Whether it's steel or iron, CNC machining continues to revolutionize industries by providing precise and efficient fabrication processes. CNC Milling CNC Machining