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What Are the Different Types Of Steel?

Steel is classified by its composition: iron is fused with carbon and any number of other elements to achieve a specific end. The four main types are:Carbon steel/Stainless steel/Alloy steel/Tool steel

Steel is classified by its composition: iron is fused with carbon and any number of other elements to achieve a specific end. The four main types are:

Carbon steel
Stainless steel
Alloy steel
Tool steel

1. Carbon Steel

While all steel contains carbon, carbon steel is unique for the notable absence of other elements in its makeup. Though it only contains 2% carbon or less by weight, its elemental nature makes carbon steel a strong, durable material that is ideal for numerous uses.

Types Of Carbon Steel

Below the 2% carbon threshold, carbon steel can be grouped into three categories: low, medium, and high carbon. Each type retains the inherent strength of carbon, but its useful purpose will change as the carbon content increases.

Low carbon: A carbon content of .30% and under is considered low-carbon steel. This is the most common and the least expensive type of steel. Thanks to its elasticity under strain, manufacturers use low-carbon steel for wires, bolts and pipes.
Medium carbon: A carbon content between 0.31% and 0.60% gives this variety a higher strength and lower ductility, meaning it’s less moldable under pressure. You can often find medium carbon steel in gears and railroad tracks.
High carbon: The toughest variety contains more than 0.61% carbon and is often used to produce extremely tough building materials and tools, like brick nails and sharp cutting tools like trencher blades. They do not contain more than 2% carbon.

2. Stainless Steel

This type is commonly known for its role in manufacturing medical equipment and appliances, but its range of use is far greater than just the gas range in your kitchen.

Types Of Stainless Steel

It’s common to see stainless steel in kitchen appliances, medical tools and automotive applications, but stainless steel is highly valued for other uses. Stainless steel is grouped into four subcategories that each serve a different purpose.

Martensitic alloys: Toughness is a hallmark of martensitic alloys, but they’re prone to corrosion. Manufacturers form these alloys with a rapid-cooling process that makes them ideal for medical instruments, cutlery and pliers.
Ferritic alloys: These are less-expensive steels with low amounts of carbon and nickel. Automotive manufacturers use ferritic alloys because of their chromium-induced strength and sheen.
Austenitic alloys: Austenitic alloys have higher chromium and nickel contents, which improves their resistance to corrosion and causes them to be non-magnetic. They’re present in commercial kitchen appliances since they’re durable and easy to clean.
Duplex alloys: A combination of austenitic and ferritic alloys results in a duplex alloy that inherits the properties of both while doubling strength. They’re also ductile and corrosion-resistant due to their fairly high chromium content. Duplex alloys are common among instruments and pipework used in gas, oil and chemical industries.

3. Alloy Steel

Alloy steel is iron fused with one of several other elements, each contributing its unique attributes to the final product. All steels are indeed alloys, but carbon and chromium are specific alloys with names attributed to the type of metal they form.

Types Of Alloy Steel

The varied potential of alloy steel allows for intense customization for specific applications. However, because the secondary elements involved are not as common as carbon or chromium, certain alloys command a steep price.

Some of the most common alloys include:

Aluminum: Lightweight, heat-resistant steel that’s ductile and easy to work with and is often used in hot exhaust systems and power generators.
Copper: Corrosion-resistant steel that conducts heat very efficiently, making it a great choice for electrical wiring and industrial heat exchangers.
Manganese: Impact-resistant steel that’s extremely tough. You can find it in bulletproof cabinets, anti-drill plates and high-strength safes.
Molybdenum: Weldable, corrosion-resistant steel that performs well under high pressure, making it suitable for underwater construction or oil and gas pipelines.
Silicon: Soft-natured steel that’s malleable and highly magnetic. Silicon creates strong permanent magnets power plants need for their electrical transformers.
Vanadium: High-impact steel that’s shock-absorbent and vibration-resistant. Automotive parts like shocks and springs often require vanadium.

4. Tool Steel

Different types of tools require different types of tool steel in production. Tool steel is used in a variety of ways to best serve the production requirements of a particular tool. Added elements will determine which particular applications that it’s suited for.

Air-hardening: The high chromium content in this steel allows it to be exposed to high temperatures without distorting.
Water-hardening: This steel is water-quenched during use, used to make common tools and is the most affordable tool steel.
Oil-hardening: This oil-quenched steel is exceptionally wear-resistant from slipping, and is used to produce knives and shears.
High-speed: High-speed steel is highly abrasive and impact-resistant. It’s found in drill bits and power saws.
Hot-working: The name gives it away, but this steel can withstand extreme heat and is used in forging and casting.
Shock-resisting: Small amounts of carbon, silicon and molybdenum harden this steel and suit it for punches and riveting tools.