Q235 Steel Plate Description

GB Q235B mild Steel is chinese standard Q235 steel series of low carbon structural steel, Q235 steel series have A, B, C , D, E quality grade. GB Q235B steel is equivalent with the European standard of DIN EN S235JR.

Related Specifications GB/T 700-1988

Chemical composition


Form of Supply

GB Q235B mild low carbon steel, we can supply the round bar, flat bar, plate, hexagonal and square block. Diameters can be sawn to your required lengths as one offs or multiple cut pieces. Rectangular pieces can be sawn from flat bar or plate to your specific sizes. Ground tool steel bar can be supplied, providing a quality precision finished bar to tight tolerances.

Q235 steel is a plain carbon structural steel which is widely used in China. Q235 material in Chinese standard GB/T 700 is divided into 4 quality grades: Q235A, Q235B, Q235C and Q235D; Density of this steel is 7.85 g/cm3 (0.284 lb/in3), tensile strength is 370-500 MPa (54-73 ksi); yield strength is 235 MPa (34 ksi) for steel bar diameter or plate thickness ≤ 16mm. Since it is mild steel, the material is commonly used directly without heat treatment. Q235 material has moderate strength, in the case of higher strength requirements, Q275 or high-strength low alloy structural steel Q355 (former Q345) can be selected.

Meaning and Designation

“Q” is the first letter of Chinese spelling of “Qufu dian”, which means Yield Point.

“235” refers to the minimum yield strength 235 MPa tested with steel bar diameter or plate thickness ≤ 16mm.

A, B, C and D represent quality grades.

Features and Applications

Q235 steel has good plasticity, toughness and weldability, as well as a moderate strength, good cold bending performance. Q235 material is commonly rolled into wire rod or round steel, square steel, flat steel, angle steel, I beam, channel steel, other sections and steel plates. These products are widely used in construction and engineering welded structures, to make steel bars or build factory buildings, high voltage transmission towers, bridges, vehicles, boilers, containers, etc., and also used as a mechanical part with less demanding performance such as less stressed rods, connecting rods, screws, nuts, ferrules, brackets, and stands, etc. Q235 STEEL PLATE

Steel wire rod made from Q235 steel in accordance with “GB/T 701 – Hot rolled carbon steel wire rods”

Q235 Steel Properties (Data Sheet and Specification)

The following tables show Q235 steel properties, datasheet and specification, including Q235A, Q235B, Q235C and Q235D steel, including chemical composition, physical and mechanical properties, etc.

Q235A, Q235B, Q235C, Q235D Steel Chemical Composition

The table below lists Q235 material chemical composition based on heat analysis.

Chemical Composition (heat analysis), %, ≤
Steel GradeQuality GradeCSiMnPSDeoxidation Method
Q235Q235A0.220.351.400.0450.050Rimmed / Killed
Q235B0.200.351.400.0450.045Rimmed / Killed
Q235D0.170.351.400.0350.035Exceptionally Killed

Note: Q235B carbon content C can be ≤0.22% by agreement.

Physical Properties


  • 10-6·K-1 = 10-6/K
  • 1 Ω·mm²/m = 1 μΩ·m
  • 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3
  • 1 GPa = 1 kN/mm2
  • 1 MPa = 1 N/mm2
Physical Properties
Density, g/cm3 (lb/in3)7.85 (0.284)
Melting point, °C (°F)1450-1530 (2640-2800)
Specific heat capacity, J/(Kg·K)470 at 20 °C (68 °F)
Electrical resistivity, μΩ·mabout 0.15 (20 °C)
Elastic modulus, GPa (ksi)200 (29 x 103)
Thermal conductivity, (W/m·K)53-49 (0-100 °C)
Coefficient of thermal expansion, (10-6/K)11.3-11.6 at 20-100 °C (68-212 °F)
Young’s modulus, GPa (ksi)200 (29 x 103)
Poisson’s ratio0.24-0.28

Mechanical Properties

Yield strength and tensile strength are listed in the table below.

1 MPa = 1 N/mm2

Yield Strength (MPa, ≥); Thickness or Dia. (d) mmTensile Strength (MPa)
Steel GradeQualityd≤1616< d ≤4040< d ≤100100< d ≤150150< d ≤200d≤100

Minimum Elongation

Elongation (≥ %); Thickness or Dia. (d) mm
Steel Graded≤4040< d ≤6060< d ≤100100< d ≤150150< d ≤200

Minimum Charpy Impact

Charpy impact (V notch)
Steel GradeQualityTemperature. °CImpact energy (longitudinal, ≥ J)

Bending Test Results of Q235 Material

Cold Bending Test 180° (B=2a)
GradeSample OrientationSteel Dia. (d) of Curve Center
d≤ 60mm60<d≤100 mm

B= Sample Steel Width; a= Sample Diameter or Thickness.

Steel rolled with Q195 and Q235B grade rimmed steel, the thickness or diameter of which is not more than 25mm.

Q235 Steel Equivalent Material

Q235steel equivalent ASTM, European EN (German DIN EN, British BS EN, French NF EN…), Australian AS/NZS, Japanese JIS, and Indian standard are listed in the table below.

Q235 Steel Equivalent Grades
ChineseUSEuropean UnionBritain (UK)AustralianJapanIndianISO
StandardGradeStandardGradeStandardGrade (Steel Number)StandardGrade (Steel Number)StandardGradeStandardGradeStandardGradeStandardGrade
GB/T 700Q235ABS 970 Prat 1080A15JIS G 3101;
JIS G 3106
SS400; SM400AIS 2062E250A
GB/T 700Q235BASTM A36;
ASTM A283/A283M
Grade D
EN 10025-2S235JR (1.0038)BS EN 10025-2S235JR
AS/NZS 3678250JIS G3101;
JIS G3106
SS400; SM400AIS 2062E250B
GB/T 700Q235CASTM A36;
ASTM A283/A283M;
ASTM A573/A573M
Grade D;
Grade 58
EN 10025-2S235J0 (1.0114)BS EN 10025-2S235J0 (1.0114)AS/NZS 3678250L0JIS G3106SM400A,
IS2062E250CISO 630-2S235B
GB/T 700Q235DASTM A36;
Grade D
EN 10025-2S235J0 (1.0114); S235J2 (1.0117)BS EN 10025-2S235J0 (1.0114); S235J2 (1.0117)AS/NZS 3678250L20JIS G3106SM400AIS2062E250 CISO630-2S235B, S235C


  • S235JRG2 and S235J2G4 are old designations in EN 10025:1993, S235JRG2 is replaced by the new designation S235JR (1.0038), and S235J2G4 replaced by S235J2 (1.0117) in EN 10025-2 since 2004.
  • Material Q235 australian equivalent is grade 250 in standard AS/NZS-3678; Indian equivalent is E250 in standard IS-2062.