Q235 steel is generally more cost-effective than many other steel grades. Its wide availability and low production cost make it an economical choice for a variety of projects. With moderate corrosion resistance, it is usually coated with a protective layer such as galvanizing, painting, or other anti-corrosion treatment to prevent rust, and can be used for outdoor structures and containers, vehicles, towers, rebars, etc. This article aims to explain the concept, characteristics, advantages, composition, and uses of Q235, and its comparison with other steel grades.

What is Q235 steel?

Q235 steel is a Chinese standard carbon structural steel. It is equivalent to ASTM A36 in the United States, SS400 Vietnam/Japanese JIS and similar to S235JR in Europe. It is divided into four grades: Q235A, Q235B, Q235C, and Q235D, with a compressive strength of 235MPa (16mm thick rebar or steel plate). Since it is a low carbon steel (up to 0.22%), it can be used in production without heat treatment.

Hardness

Hardness indicates the ability of Q235 steel to resist deformation and wear. Although Q235 steel is not as hard as some other steel, it provides sufficient hardness for many practical applications. The Brinell hardness of Q235 steel is usually about 100-130 HB. This moderate hardness ensures good machinability and workability while providing sufficient wear resistance for many uses.

Yield Strength

Q: represents the yield point (σs),

235: represents the yield strength,

Q235 represents the pressure that the steel can withstand per unit area, which is 235MPa.

It has good plasticity and toughness, is easy to process and weld, and has a relatively low price.

Q235 A,B,C,D Mechanical Properties

Tensile Strength: The tensile strength of Q235 steel is usually between 370 and 500MPa.

The minimum yield strength of Q235 steel is 235MPa.

Elongation: The elongation at break of Q235 steel is usually about 26%.

(TSET SAMPLE: 16mm steel bar(Mpa=N/mm2))

Physical properties

Physical Properties
Density, g/cm3	7.85
Melting point, ℃	about 1493
Specific heat capacity, J/(Kg·K)	470 at 20 ℃
Electrical resistivity, μΩ·m	about 0,15 (20 ℃)
Elastic modulus, GPa (kN/mm2)	200
Thermal conductivity, (W/m·K)	53-49 (0-100 ℃)
Coefficient of thermal expansion, (10-6/K)	11.3-11.6 (20 ℃)
Young’s modulus, GPa (kN/mm2)	200
Poisson’s ratio	0.24-0.28

Uses

It is popular in general structural applications such as buildings, bridges and machines. It can be rolled into wire rod or round steel, square steel, flat steel, angle steel, I-beam, channel steel, other profiles and steel plates. These products are widely used in welding structures in construction projects, making steel bars or building plants, high-voltage transmission towers, bridges, vehicles, boilers, containers, etc., and can also be used as mechanical parts with low performance requirements, such as rods, connecting rods, screws, nuts, rings, scaffolding, brackets, etc. with less stress. In addition, Q235 steel is often used as the raw material for galvanized steel and other coated steel products.

· Metal furniture frames

· Gearbox and engine parts

· Agricultural machinery

· Railway tracks

· Purlin and roof structures

· Structural beams and columns

· Tool cabinets and workbenches

· Office desks and chairs

Features

1. Low carbon content: Q235 steel has a carbon content of less than 0.22%, ensuring its excellent weldability and formability. The low carbon content also reduces the risk of brittleness during manufacturing and improves the ductility of the material.

2. High tensile strength: Typically between 370 and 500 MPa. This high strength enables it to withstand heavy loads and is suitable for structural applications.

3. Good ductility and toughness: It can be stretched or bent without breaking. In addition, good toughness enables it to absorb energy and resist breaking under impact or dynamic load conditions.

4. Excellent weldability: Q235 steel has extremely high weldability and can be easily connected by various welding methods, including arc welding, resistance welding and gas welding. It forms a strong and reliable weld for efficient manufacturing and construction.

5. Wide range of uses: Commonly used in structural parts such as beams, columns, trusses, etc. in buildings and bridges, and is also used in the manufacture of machinery, automotive parts, general steel, etc.

6. Corrosion resistance: Galvanized Q235, coated Q235 steel enhances its inherent corrosion resistance.

7. Hardness: Q235 steel has medium hardness, which contributes to its machinability. It can be easily cut and drilled using common tools.

8. Compliance with quality standards: Q235 steel plates adhere to strict quality standards, including Chinese standards (PRC) and international standards such as JIS (Japan), ASTM (USA), DIN (Germany), and EN (Europe).

9. Variety of sizes: Width from 1510mm to 2300mm, thickness from 1.5mm to 100mm, length from 6m to 12m. Wanzhi Steel provides full-size customization and all processing services.

Chemical composition

The chemical composition of Q235 steel includes carbon (C), silicon (Si), manganese (Mn), sulfur (S), phosphorus (P) and other elements. Among them, carbon, silicon and manganese are the main alloying elements, which play a major role in the mechanical properties of steel.

According to the Chinese national standard GB/T 700, the chemical composition (mass percentage) of Q235 steel is as follows:

1. Carbon (C): 0.14-0.22%

2. Silicon (Si): ≤0.35%

3. Manganese (Mn): 0.30-0.70%

4. Phosphorus (P): ≤0.045%

5. Sulfur (S): ≤0.045%

These elements work together to give steel its strength, toughness, and weldability.

Q235 Carbon Steel Grade Comparison

According to the GB/T 700-2006 standard, carbon structural steel Q235 is divided into four categories: A, B, C, and D according to metallurgical quality.

Steel grade	Carbon (C %)≤	Silicon (Si %)≤	Manganese (%) ≤	Phosphorus (P%) ≤	Sulfur (S%) ≤
Q235A	0.22	0.35	1.4	0.045	0.05
Q235B	0.2	0.35	1.4	0.045	0.045
Q235C	0.17	0.35	1.4	0.04	0.04
Q235D	0.17	0.35	1.4	0.035	0.035
Quality Greade: A≤B＜C＜D

Q235 steel quality is increased from grade A to grade D. This increase in grade is reflected in the reduction of the maximum allowable percentages of carbon (C), phosphorus (P), and sulfur (S). Lower carbon content generally increases flexibility, while lower phosphorus and sulfur content increases the toughness and weldability of the steel.

Comparison of Q235A/B/C/D characteristics and applications

Q235	Q235A	Q235B	Q235C	Q235D
Properties	Basic version of q235	Better quality than Q235A, with slightly better mechanical properties	Q235C has enhanced performance, especially in low temperature environments	Q235D’s strongest performance, especially in low temperature environments
Features	Good weldability and formability Yield strength: 235MPa Tensile strength: 370-500MPa Elongation: about 26%	Improved toughness Better weldability Slightly higher tensile strength and elongation	Improved impact resistance at low temperatures Yield strength: 235MPa Tensile strength: 370-500MPa Elongation: 20-23%, depending on the specific grade	Improve impact resistance at low temperatures Yield strength: 235MPa Tensile strength: 370-500MPa Elongation: 20-23%
Applications	Building frames Bridges Structural beams General Manufacturing	Heavy construction projects Machinery parts Automotive parts Large steel structures	Offshore structures; Cold storage facilities; Bridges in cold climates; Highly stressed structural components	Applications for better toughness and durability Cold storage facilities Bridges in cold climates Offshore structures Highly stressed structural components

 

Comparison of the features of Q235 and A36/S235/SS400/Q345

	Q235	A36	S235	SS400	Q345
Features	Yield strength 235 MPa Tensile strength 370-500 MPa Silicon and manganese content slightly higher than A36 Compared with the old standard GB700-79 grades, Q235 is equivalent to A3, C3 and other grades	Yield strength is about 235 MPa Tensile strength ranges from 400-550 MPa	Very similar to Q235 in mechanical properties, slightly different in chemical composition	SS400 is a Japanese standard steel with similar mechanical properties to Q235 Good weldability and machinability	Yield strength is 345MPa Low alloy steel with higher strength and toughness Equivalent to 12MnV, 16Mn, 16MnRE, 18Nb, 14MnNb and other grades.
Application	General construction, structural parts and mechanical parts manufacturing	It is widely used in the United States for structural applications such as building frames, bridges and oil rigs.	Construction industry, oil and gas industry, water transport industry as well as structural applications and conveying of fluids and gases.	Ideal for wastewater treatment facilities, customers seeking high-quality, durable, strong and reliable pipes, oil and gas industry or water transport industry	High-rise buildings, large bridges, heavy machinery, oil and gas pipelines, etc.
Cost	Cheap	Relatively expensive	Slightly more expensive than Q235	Cheap	Relatively high

Q235 VS. ASTM A36, S235, SS400 and E250 Steel

A36, SS400, S235JR, and E250 steels have a similar chemical composition and mechanical properties to Q235 steel and are all carbon structural steels.

 

Table 1 – Comparison of chemical composition

			Chemical Composition % (≤)
Country	Standard	Steel Grade	Quality Grade	C	Si	Mn	P	S	Cu	N
China	GB/T 700	Q235	Q235A	0.22	0.35	1.40	0.045	0.050	0.30	0.012
			Q235B	0.20	0.35	1.40	0.045	0.045	0.30	0.012
			Q235C	0.17	0.35	1.40	0.040	0.040	0.30	0.012
			Q235D	0.17	0.35	1.40	0.035	0.035	0.30	0.012
US	ASTM A36	A36		0.26	0.40	1.35	0.040	0.050	0.20	–
European	EN 10025-2	S235	S235JR (1.0038)	0.17	–	1.40	0.035	0.035	0.55	0.012
			S235J0 (1.0114)	0.17	–	1.40	0.030	0.030	0.55	0.012
			S235J2 (1.0117)	0.17	–	1.40	0.025	0.025	0.55	–
Japan	JIS G3101	SS400		–	–	–	0.050	0.050	–	–
India	IS 2062	E250	E250A	0.23	0.040	1.50	0.045	0.045	0.20-0.35	0.012
			E250B	0.22	0.040	1.50	0.045	0.045	0.20-0.35	0.012
			E250C	0.20	0.040	1.50	0.040	0.040	0.20-0.35	0.012

 

Table 2-Yield Strength Comparison

	Yield Strength (≥ N/mm2); Dia. (d) mm							Tensile Strength
Country	Steel Grade	d≤16	16 < d ≤40	40 < d ≤60	60 < d ≤100	100 < d ≤150	150 < d ≤200	N/mm2
China	Q235	235	225	215	215	195	185	370-500
US	A36	250 MPa (d ≤ 200mm)						400-550
European	S235	235	225	215	215	195	185	360-510
Japan	SS400	245	235	215	215	205	205	400-510

S235 has 3 quality grades, including S235JR, S235J0 and S235J2.

 

Table 3 – India Standard

		Yield Strength (≥ N/mm2); Dia. (d) mm				Tensile Strength
Country	Standard	Steel Grade	d<20	20 ≤ d ≤40	>40	N/mm2
India	IS 2062	E250	250	240	230	≥ 410

1MPa = 1 N/mm2.

 Q235 Steel Equivalent Standard

China	USA	Germany	Japanese	France	UK	ISO
GB	ASTM	DIN	JIS	NF	BS	ISO
Q235A Steel	Gr.D (σS230MPa)	Ust37-2 RSt37-2	SS440 SM400A (σS245MPa)		080A15 (σS235MPa)	E235B (σS235MPa)
Q235B Steel	Gr.D (σS230MPa)	S235JR S235JRG1 S235JRG2 (σS235MPa)	SS440 SM400A (σS245MPa)	S235JR S235JRG1 S235JRG2 (σS185MPa)	080A15 S235JR S235JRG1 S235JRG2 (σS185MPa)	E235B (σS235MPa)
Q235C Steel	Gr.D (σS230MPa) Gr.65 (σS240MPa)	S235JO (σS235MPa)	SM400A SM400B (σS245MPa)	S235JO (σS235MPa)	080A15 S235JO (σS235MPa)	E235C (σS235MPa)
Q235D Steel	Gr.D (σS230MPa)	S235J2G3 S235J2G4 (σS235MPa)	SM400A (σS245MPa)	S235J2G3 S235J2G4 (σS235MPa)	S235J2G3 S235J2G4 (σS235MPa)	E235D (σS235MPa)

 

If you want to know the price of Q235 or other steel, please feel free to consult our professional technicians. We will be happy to help you.

In addition, the Q235 HR Sheet and coil, steel wire rods, Galvanized Concrete Mesh, and q235 Galvanised Welded Mesh Panel are our most popular Q235 Steel products.

 

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