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Everything You Need to Know About Steel

What is steel

Steel definition it that, it’s an alloy of iron with carbon and a lot of other materials that are in really small quantities. This improved strength and made it more resistant to fractures compared to other forms of iron.

What is steel made of?

Steel is an alloy of iron and carbon, so steel is made mainly of iron and carbon. The composition of steel varies based on the type or grade of steel. The most widespread compositions of steel are carbon steel which is around 98-99% iron and 0.05- 2.1% carbon. 

Other elements such as manganese, phosphorus, sulfur, and silicon, may also be present in minimal quantities. Additional elements in required amounts (e.g. strength, hardness, corrosion resistance, and machinability) are incorporated into the steel properties so that it can meet the diverse demands of different application areas.

Different types of steel

What is Carbon Steel

Carbon steel refers to a type of steel material with only carbon as an alloying element. It has gray and muted colors and is known to be highly resistant to corrosion. There are three different types of carbon steel based on the content of carbon in steel. These types are low, medium, and high carbon steel. 


Low carbon steel contains about 0.30%, medium one has 0.60%, and high carbon steel has up to 2.1% of carbon. The name itself comes from the quality that it has a very minimal amount of other elements. 

Carbon steel has exceptionally good strength, which is the reason carbon steel is often used to make things like railway tracks, wires, bolts, pipes, and other similar items.

What is Alloy Steel

Alloy steel is a mixture of several metals, like Molybdenum, copper, and aluminum. This type of steel is likely to be more on the cheaper side and more resistant to corrosion.

The strength of alloy steel material depends on the concentration of the elements it contains. There are several common types of alloy steel


  • Alloy Steel Containing Aluminum: Alloy Steel that has heat-resistant characteristics. It has high ductility and is easy to weld and used in exhaust systems and power generators.

  • Alloy Steel Containing Copper: it is a Corrosion-resistant type of steel material with high thermal conductivity characteristics. This type of alloy steel is a good material for electrical wiring and industrial heat exchangers.

  • Alloy Steel Containing Manganese: This alloy steel is very tough and durable. It has its most uses in bulletproof cabinets, anti-drill plates, and high-strength safes.

  • Alloy Steel Containing Molybdenum: This is a corrosion-resistant, high-pressure, weldable, steel that has uses for submerged structures and oil and gas pipelines.

  • Alloy Steel Containing Vanadium: This alloy steel material has High-impact resistance capacity which make it not only shock absorbent but also vibration resistant. Automotive parts such as shocks and springs use vanadium alloy steel.

What is Tool Steel

It’s a high carbon steel that is used in manufacturing of machining tools like drill bits and mill cutters. All similar items like drills, saw blades, and a variety of tool bits, are often manufactured with tool steel. 

Carbon along with other metals, including tungsten, chromium, and vanadium, boosts the strength of steel and makes it harder and resistant to wear and corrosion. The process of tool steel making is called Tempering. 


It is simply the process of putting in high heat, then cooling off instantly and finally heating it back. The tool steel has great hardness and heat resistance. This group of steel material is hard to sharpen and resistant to high-impact situations.

What is Stainless Steel

Stainless steel is the widest-spread variety of steel across the globe. Its composition approximately consists of 10% to 20% chromium. This feature of stainless steel makes it corrosion-resistant.

Kitchen appliances, including stoves, refrigerators, and microwaves, usually have a stainless steel exterior, and they play a vital role in medical tools like surgical blades and automotive devices. Stainless steel material (SS) is divided into four subcategories that are manufactured to do distinct kinds of work.

  • Martensitic alloys: Toughness is particular for martensitic alloys, and they deter corrosion. During the manufacturing process, manufacturers fuse alloys that afterward serve various purposes and make steel compatible for manufacturing of medical instruments, cutlery, and pliers.


  • Ferritic alloys: These are cheap steels with less carbon and nickel than other types of steel. The easiest explanation for the usage of ferritic alloys is based on chromium being a component that contributes to the strength and “shiny” appearance of the steel material.

  • Austenitic alloys: Austenitic alloys contain higher chromium and nickel levels, which results in better corrosion resistance and causes the alloy to be nonmagnetic. They can be found in a variety of typical commercial kitchen appliances because they are reliable and simple to clean.

Physical Properties of Steel

1. Density: Steel metal is a type of metal that has an average density of 7.85g/cm3. This makes steel a moderate heavy metal as compared to other materials of equivalent strength.

2. Corrosion Resistance: The ability of the steel metal to withstand the effects of corrosion relies on its composition and surface treatment. Considering the nickel inclusion, the steel becomes resistant to corrosion due to chromium which creates a protective oxide layer.

3. Thermal Expansion: When steel is heated it expands then returns to its original size when cold. The value of thermal expansion coefficient for steel also depends on its  composition but it is usually from around 10 to 12 µm/m°C.

4. Thermal Conductivity: Steel metal has good heat conductivity characteristics with thermal conductivity which varies between 15 and 50 W/m °C mainly depending on its composition and structure.

5. Electrical Conductivity: While steel is not frequently used as a conductor for electrical purposes due to its rather low electrical conductivity compared to the likes of copper and aluminum, it however still conducts an electrical current to a certain extent.

6. Boiling Point: Not a defined boiling point property because the steel is not a pure substance. This material consists of a combination of carbon, iron, and other added elements. On the other hand, the melting point of iron, which is the main element in steel, goes up to about 2,862°C (5,184°F).

7. Melting Point: The melting point of steel metal too is also affected by its composition in a similar fashion. Pure iron melts at about 1,535°C (2,795°F), while the addition of carbon and other alloying elements makes the steel melt point to be higher. Generally, steel melt ranges between 1,370 to 1,540°C (2,500 to 2,800°F); this depends on the composition.


Mechanical Properties of Steel

1. Yield Strength: The term yield strength denotes the case in which the level of stress acting on the materials is higher than the strain leading to permanent deformation. This procedure is a limit that material can't be stretched more without a lasting distortion. The tensile strength of steel varies from 250 MPa to over 1000 MPa.

2. Ultimate Tensile Strength (UTS): The ultimate tensile strength of the material can be interpreted as the strength of the material to withstand damage without fracture when tension is applied. Steel qualities vary according to the chemistry of the material and how the process was performed. The range is 400 MPa to 2000 MPa.

3. Hardness: Hardness is the durability of fabric features, which refers to the resistance to a deformation that occurs by pressure or scratching. Specialized instruments as well as techniques like Brinell, Rockwell, and Vickers scales are used to measure the level of hardness in steel. Both the steel components and also given microstructure and heat treatment will lead to a certain hardness of steel. Generally steel offers a Rockwell hardness number of 60.

4. Toughness: Toughness is the property of the material that it will be deformed plastically before it fails. It combines the hardness and ductility that are the ability to stand sudden loading or impact. The toughness of steel is influenced by factors such as the composition, grain size as well as notch sensitivity.

5. Fatigue Strength: Fatigue strength denotes the maximum stress that the material can sustain in a predetermined number of load cycles before failure under dynamic loading. The factor of steel's fatigue strength is the function of such characteristics as composition, microstructure, surface condition, and load conditions.

6. Elasticity: Elasticity is the capacity of the material to deform under stress and return to its original shape when the stress is released. Once the steel is stressed and deforms plastically inside the elastic limit (190 GPa to 210 GPa), it goes back to its normal shape once the stress is released.

7. Plasticity: Plasticity in material is the attribute that when a stress beyond the elastic limit is applied, the material gets permanently deformed without breaking into pieces. Unlike steel which behaves elastically by going back to its original shape after removal of the stress, steel behaves plastically such that it deforms irreversibly under the stress.

Chemical Properties of Steel

1. Texture: Steel texture varies a lot. From shiny surfaces to dull dark black appearance. Steel textures are generally referred to as surface configurations or micro-structures. These vary in consistency with manufacturing processes and time of treatment. If it is important to obtain smoothness when using it in the woodwork to get either a smooth and even finish or a rough and coarse texture, this might be an option.

2. Toxicity: Unlike the rest of the toxic materials, the major composition of steel is iron and carbon. Some metals that are present only in minor quantities can be nontoxic. The steel grade, coating, or surface treatment employed may be hazardous. 

3. Flammability: Steel is considered non-combustible. Its trituration index is high and non-flammable under standard conditions. However, the structural strength and integrity of steel may be diminished in case of thermal exposure at high temperatures occurring for a long period which may result in the collapse of the structure as seen in fire situations.

4. Reactivity: Steel is very durable and insensitive to changes in the environment. But it could also develop or lead the waste products during contact with some elements or conditions. The steel reactivity will be changed if there is a change in steel composition, steel surface condition as well as exposure to corrosive agents such as moisture, acid, or alkalis among others.

5. Oxidation: The rusting process mainly occurs with the help of oxygen and water. Hence, the surface of the steel especially gets oxidized and then the iron oxide is formed.

6. Solubility: Steel is soluble in hydrocarbons and is the dominant liquid of organic nature. However, even if acid and alkaline solutions are applied, they can contribute to surface attack of the steel.

What are some advantages of using steel?

1. Steel is known to be one of the strongest materials available to the general public on a larger scale and is affordable too. This is the reason why it is used for heavy-duty applications in construction, stainless steel deep drawing manufacturing, and many more

2. While steel can be shaped into different forms and dimensions, this provides an element of variety in design and usage. It may be adjusted to meet some demands in different branches of business.

3. Steel has a great tensile strength and it can withstand heavy loading without being deformed or failing. This is the reason it is predominantly used in structural applications that need considerable strength.

4. Different types of steel are invented to prevent corrosion which not only extend their life but also reduce maintenance costs. For example, stainless steel contains chromium that creates an oxide layer on the surface and protects the steel from rusting.

5. Steel is the world's most recyclable commodity. It keeps properties, even after recycling, which gives it a higher sustainability score for those who are environmentally conscious. Recycling steel decreases demand for virgin materials and energy conservation.

6. Even though some materials are better than steel materials, it could be cost-effective in the long run, because of its durability, low maintenance as well as recyclability.

7. Steel is resistant to fire and thus can be used for fire safety. This capability is relevant in the construction and industrial sectors where fire protection is highly important.

What are the advantages and disadvantages of steel?

What are some limitations of steel?

1. Corrosion: Some types of steel are resistant to corrosion while others corrode when they occur in moisture or certain chemicals. If it is left without maintenance and paint, metallic structures will become a risk for structural safety and integrity.

2. Weight: The high density of steel as compared to other construction materials contributes to the increase in the structure’s mass. This could be challenging for certain purposes, and an example could be when the weight is critical, such as in the aviation or aerospace industries.

3. Fire Resistance: Steel is not immune to strength loss under high temperatures. Steel could lose strength and deform after an extended period of being exposed to fire.

4. Brittleness: From time to time, steel may terminate as brittle material, especially when the temperature is not well above room temperature. This would consequently lead to the polar side cracks during underload or off the intended impulse.

5. Magnetic Properties: The properties of different types of steel vary markedly. Some of them have magnetic characteristics that are not acceptable in other markets that steel which area the magnet interference is not acceptable.

6. Vibrations: Vibration of noise along steel components is much faster than with other materials which could be a prospective drawback in sound absorption areas.

What are some applications of steel?

1. Construction: Buildings, bridges, skyscrapers, and even stadium constructions have widely adopted steel making use of its high strength, durability, and resistance to loads.

2. Infrastructure: The strength and capabilities of the road and rail infrastructure, airports, and underground tunnels are built of steel, which is highly adaptable to both bad and good conditions.

3. Transportation: In car body manufacture other than for the automobile industry where steel is predominantly used for its strength-by-weight ratio and collision-resistive abilities, steel is also present in construction and aerospace in the making of bridges, buildings, air crafts, and ships.

4. Machinery and Equipment: Steel, due to its hardness, wear, and moldability, is often the first choice of metal for making machines, equipment, and tools. Steel is also a raw material when making metal products.

5. Defense and Security: Steel is well acknowledged to be used for the production of gun-resistant buses, armored walls, and security fencing because of its strength, hardness, and resilience to impact.


Steel is a unique material, that is almost all of iron and carbon with additional elements, capable of presenting many useful functions and applications. 

The properties of this material are represented in the physical, mechanical, and chemical such as high density, strength, corrosion resistance, and recyclability. 

Advantages such as durability, fire resistance, and the ability to build complicated shapes, however, limitations such as susceptibility to corrosion and environmental impact are also related to it. 

Steel plays a role in the construction industry, transportation, machinery, packing, defense, and medical equipment, being the one to do among other industries.