Overview Chromoly Steel - The Sustainable Steel Standard For Future

Overview Chromoly Steel - The Sustainable Steel Standard For Future

BlogDate: 15-01-2024 by: Ngan Le

Besides the usual steels, today manufacturers have continuously innovated and released many improved steel alloys to serve diversified industries. Chromoly steel is known as a steel alloy that is lighter in weight than any other steel, but it also ensures good durability and load capacity.

What is Chromoly steel and its important specifications

Chromoly steel is a low-alloy heat-resistant steel formed by a combination of "chromium" and "molybdenum", of which the chromium content is 10%. The role of alloying elements will make the product have superior features to ordinary carbon steels because it helps increase durability after undergoing heat treatment.

The Chromoly steel grades are conventionally identified by the first two digits of 41, to indicate that this is the designation of chromium and molybdenum steels. An example of the most common type of Chromoly steel can be mentioned as AISI 4130 steel which is currently being used a lot in the oil and gas, aerospace,...



Carbon 0.28 – 0.33


Manganese 0.40 – 0.60


Phosphorus 0.035 max


Sulfur 0.040 max


Silicon 0.20 – 0.35


Chromium 0.80 – 1.10


Molybdenum 0.15 – 0.25

Some remarkable properties of chromoly steel 

Limitation in metal corrosion

Chromium is known as a metal with very high hardness, it also has amazing corrosion resistance. When chromium meets oxygen, it will form a compound Cr2O3, which is the strongest compound of chromium in anti-oxidation. So if Chromium is added to steel, it will create a more protective layer for the steel core, the more chromium content, the higher the steel's ability to resist rust.

Outstanding hardness

Similar to chromium material, when adding the molybdenum to the structure of steel, it will provide superior strength as it increases the hardness of steel and of course, the tensile strength of steel will be greatly improved. A chromium molybdenum steel plate can be designed to withstand a load force of up to 760 MPa.

Thanks to this ideal hardness, Chromoly steel helps to maintain the stability of the structure, increase the load-carrying capacity, and minimize the product's warping or distortion when subjected to long-term loads.

Good heat resistance

Beyond the feature of increasing hardness, chromoly steel also possesses good heat resistance properties because molybdenum compound allows the steel to survive well under temperatures up to 5800C. Molypden is a heat resistant substance in nature, when combined with chromium, this link will significantly reduce the damage of steel structures in high pressure environments.

Long-term cost savings

Chromoly steel will cost more than standard steel grades, but in terms of its useful applications in the long-term, this steel will provide the amount of cost-effectiveness for plan. If you are looking for a material that is stronger and lighter than steel but not as expensive as titanium, chromoly steel will be the best choice for you.

List of common Chromoly steel's applications 

Basically, Chromoly steel has some similar features to standard carbon steel, but thanks to the addition of a chromium layer, the steel has enhanced strength and resistance to oxidation, the molybdenum content in the steel also increases toughness. Because of these superior features, the Chromoly steel line becomes useful and is being applied to many industries.

Aerospace industry

In the past, steel and aluminum were the popular materials in the aviation industry, but in recent decades, chromium steels are gradually being applied and replacing traditional materials. Thanks to its thermomechanical properties, chromoly steel is often used to support jet engines and landing systems.

Manufacture of vehicles and bicycles

Due to the versatile combination of durability properties as well as good load bearing, Chromoly steel is often used to make car chassis. Moreover, based on the advantages of anti-corrosion and high hardness, manufacturers often use them to make gears and automobile crankshafts.

Chromoly steel is considered the best material for bicycles. Although Chromoly is known for its hardness beyond standard, it also possesses surprisingly good ductility. Thanks to this factor, manufacturers can freely shape and weld metal parts together to create trendy chassis models that still ensure good durability and bearing capacity.

Chemical industries

Many studies have proved that Chromoly steel can suffer from extreme environmental temperature conditions up to 5800C for a long time. Therefore, this steel is widely used in high pressure industries such as oil filtration and chemicals.

Depending on the numerous advantages that Chromoly steel brings, it is not difficult to imagine that Chromoly steel will become a standard material for many applications of the field in the future. Therefore, preparing a plan to add Chromoly steel as the main sources for your projects will be a perfect decision for future sustainable development.

If you are in need of sourcing reputable Chromoly steel as well as learning more about price segments in the Vietnamese steel market, please contact MRS Steel via Whatsapp +84 76 911 2358 or email