What is Q235 Steel – Q235 Properties, Characteristics, Applications & Comparison


Q235 steel is an important metal material used in the building and construction industry, in this article, we get into an overview of Q235, dive into what is Q235, its properties, characteristics, applications, and differences between Q235A, Q235B, Q235C, and Q235D.

What is Q235 Steel?

Q235 steel, which is previously known as A3, is a carbon structural steel. Q represents the yield point of this material, and the following number 235 refers to the yield strength of this material, which is about 235MPa. Generally, steel is used directly without heat treatment. 

Properties of Q235 Steel

Ultimate Tensile Strength: 370-500 MPa

Yield Tensile Strength: 235 MPa

Elongation at Break: 20-26%

Modulus of Elasticity: 200 GPa

Compressive Yield Strength: 152 MPa

Bulk Modulus:160 GPa

Poissons Ratio: 0.26

Shear Modulus: 79.3 GPa

Characteristics of Q235 Steel

Understanding more about the material characteristics will help you better use it. 

Q235 is a carbon structural steel. Carbon steel is an alloy mainly composed of iron and carbon, but the carbon content is less than 2%. Generally, it also contains a small amount of silicon, manganese, sulfur, phosphorus, and other elements. Carbon steel with sulfur and phosphorus content greater than 0.35% but less than 0.5% by mass is called ordinary carbon steel. High-quality carbon steel and high-quality steel have lower sulfur content, and the latter has less than 0.3% sulfur and phosphorus content.


Q235 is medium and low-strength steel. Its yield strength is 235Mpa, and its strength in steel materials is relatively low. Steels with higher strength, such as Q345, medium strength steel, while those with higher strength, such as Q420D, high strength steel. There are also special ultra-high-strength steels, such as GC-4 steel, whose tensile strength reaches 1765-1961Mpa.


Q235 is a type of steel with good plasticity and toughness. Good toughness of steel is a very important advantage, because in engineering, if the toughness is low, then brittle fracture may occur, and brittle fracture occurs very quickly, causing great damage.


Q235 is easy to weld. Because the general welding process is carried out at room temperature, the cooling rate of weld metal droplets is very fast. In addition, the fusion of raw materials and welding materials leads to a very intense solidification process. We can regard the weld as a defective solidification. The advantage of Q235 steel is that it contains fewer harmful elements, such as S and P, and it is not easy to produce segregation that can seriously affect the weld quality. At the same time, its carbon content is not high, and it is not easy to cause hot cracks in the weld due to the enrichment of carbon in the weld.


Q235 is easy to corrode and rust, but not in reinforced concrete. Q235 steel contains carbon, phosphorus, manganese, silicon, and other components and impurities, and forms ferrite, pearlite, austenite, and other different solid solution forms at the same time. When there are conductive substances such as water film on the steel surface, different components in the steel show different potentials, which is easy to lead to an electrochemical reaction.

Q235A vs Q235B vs Q235C vs Q235D

In the GB/T 700-2006 standard, the carbon structural steel Q235 is divided into four grades: A, B, C, and D according to the metallurgical quality. The chemical composition of Q235A, B, C, and D is different. The sulfur content of A, B, C, and D decreases successively, the phosphorus content of A and B is the same, followed by that of C, and the phosphorus content of D is the least. Different grades of Q235A, Q235B, Q235C, and Q235D represent different impact temperatures. A means no impact, B is above 20 degrees, C is above 0 degrees, and D is above – 20 degrees.

Uses and Applications of Q235 Steel

Q235 is widely used in ordinary concrete structures as hot-rolled plain steel, also used in secondary reinforcement or erection reinforcement, as carbon structural steel. In addition, hot-rolled ribbed steel bars are also widely used in ordinary concrete. According to GB1499 and GB50010-2002, the codes are HRB335 or HRB400.


Q235 steel is also widely used in the formwork of reinforced concrete construction projects. The combined formwork uses Q235 hot-rolled steel plate with a basic material thickness of 2.5~3mm, a Q235 hot-rolled plate with a thickness of 5~6mm is used for all steel large formwork.


A large number of nonimportant steel structures use Q235 steel. In the project, most steel supports are made of steel pipes with a diameter of 48mm and grade of Q235, and a few steel pipes with a diameter of 42mm are used to make gate-shaped and square tower-shaped supports.


If you are looking for a steel machining company for Q235 or other grades, welcome to send your CAD drawings to CNCLATHING.