Q235 steel equivalent, properties, specifications, and composition

What is Q235 Steel (Q235A Q235B Q235C Q235D)

Q235 steel is a common type of carbon structural steel used in China. The Chinese standard GB/T 700 divides Q235 into four grades: Q235A, Q235B, Q235C, and Q235D. Its density is 7.85 g/cm³. The tensile strength ranges from 370 to 500 MPa, while the yield strength is 235 MPa. These values apply to steel bars or plates with a diameter of 16 mm or less. Because it’s mild steel, people use it without undergoing a heat treatment process.

“Q” is the first letter of the Chinese word “屈服点”, and its corresponding English term is “Qu Fu Dian”, which means the yield point of a metal.

“235” refers to the minimum yield strength value of 235 megapascals obtained from the test using steel with a diameter of 16 millimeters.

Properties and Application of Q235 steel

Engineers recognize Q235 steel for its great plasticity and toughness. It also has good weldability and strength. Plus, it performs well in cold bending. Q235 materials are often shaped into various forms. These include wire rods, round steel, square steel, flat steel, angle steel, I-beams, channel steel, and other profiles. Steel plates are also made from Q235 materials.

These products are common in construction and welding. They help make reinforcing bars, factories, high-voltage towers, bridges, vehicles, boilers, and containers.

You can also use them for low-performance mechanical parts. Examples are rods under light stress, connecting rods, screws, nuts, bushings, supports, and brackets.

Q235 steel Specification Data Sheet

Chemical composition table of Q235 material based on thermal analysis

Chemical Composition (heat analysis), %, ≤
Steel Grade	Quality Grade	C	Si	Mn	P	S	Deoxidation Method
Q235	Q235A	0.22	0.35	1.40	0.045	0.050	Rimmed / Killed
	Q235B	0.20	0.35	1.40	0.045	0.045	Rimmed / Killed
	Q235C	0.17	0.35	1.40	0.040	0.040	Killed
	Q235D	0.17	0.35	1.40	0.035	0.035	Exceptionally Killed

The physical and mechanical properties of Q235 steel

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

Yield strength and tensile strength

	Yield Strength (MPa, ≥); Thickness or Dia. (d) mm					Tensile Strength (MPa)
Steel Grade	Quality	d≤16	16< d ≤40	40< d ≤100	100< d ≤150	150< d ≤200	d≤100
Q235	Q235A	235	225	215	195	185	370-500
	Q235B
	Q235C
	Q235D

Minimum elongation

	Elongation (≥ %); Thickness or Dia. (d) mm
Steel Grade	d≤40	40< d ≤60	60< d ≤100	100< d ≤150	150< d ≤200
Q235	26	25	24	22	21

Charpy Impact Test

		Charpy impact (V notch)
Steel Grade	Quality	Temp. ℃	Impact energy (longitudinal, ≥ J)
Q235	Q235A	–	–
	Q235B	+20	27
	Q235C	0
	Q235D	-20

Q235 Steel 180° Cold Bending Test

Cold Bending Test 180° (B=2a)
Grade	Sample Orientation	Steel Dia. (d) of Curve Center
		d≤ 60mm	60<d≤100 mm=””></d≤100>
Q235	Vertical	a	2a
	Horizontal	1.5a	2.5a

B = Sample width; a = Sample diameter or thickness.
Steel strips – Q195 and Q235B grade open-molded steel, with a thickness or diameter not exceeding 25mm.