Q235 steel is a widely used low-carbon structural steel originating in China and recognized internationally. It is valued for its balanced mechanical properties, weldability, ductility, and cost-effectiveness, making it suitable for construction, machinery, vehicle chassis, bridges, and industrial applications.
Yield Strength: 235 MPa (for thickness ≤16 mm)
Tensile Strength: 370–500 MPa
Elongation: 21–26% (depending on thickness)
Density: 7.85 g/cm³
Melting Point: 1420–1460 °C
Q235 Grades:
Q235A: General structural use, moderate strength, good plasticity
Q235B: Most common, better toughness and impact resistance (+20 °C)
Q235C: Suitable for low-temperature environments (0 °C)
Q235D: High-quality grade for very low temperatures (-20 °C)
Chemical Composition (Typical, Heat Analysis, %)
| Grade | C | Si | Mn | P | S |
|---|---|---|---|---|---|
| Q235A | ≤0.22 | ≤0.35 | ≤1.40 | ≤0.045 | ≤0.050 |
| Q235B | ≤0.20 | ≤0.35 | ≤1.40 | ≤0.045 | ≤0.045 |
| Q235C | ≤0.17 | ≤0.35 | ≤1.40 | ≤0.040 | ≤0.040 |
| Q235D | ≤0.17 | ≤0.35 | ≤1.40 | ≤0.035 | ≤0.035 |
Mechanical Properties by Thickness (mm)
| Thickness | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|
| ≤16 | ≥235 | 370–500 | ≥26 |
| 16–40 | ≥225 | 370–500 | ≥26 |
| 40–60 | ≥215 | 370–500 | ≥25 |
| 60–100 | ≥215 | 370–500 | ≥24 |
| 100–150 | ≥195 | 370–500 | ≥22 |
| 150–200 | ≥185 | 370–500 | ≥21 |
Impact Resistance (Charpy V-notch)
| Grade | Min Temp | Min Impact Energy (J) |
|---|---|---|
| Q235A | Not specified | - |
| Q235B | +20 °C | ≥27 |
| Q235C | 0 °C | ≥27 |
| Q235D | -20 °C | ≥27 |
Global Equivalents
| China GB/T 700 | US ASTM | Japan JIS | EU EN / UK BS | Australia | India |
|---|---|---|---|---|---|
| Q235A | - | SS400, SM400A | - | - | E250A |
| Q235B | A36 / A283 | SS400, SM400A | S235JR | 250 | E250B |
| Q235C | A36 / A573 | SM400A, SM400B | S235J0 | 250L0 | E250C |
| Q235D | A36 / A283M | SM400A | S235J0 / S235J2 | 250L20 | E250C |
Applications of Q235 Steel Pipes
Construction & Infrastructure: Building frameworks, bridge components, structural supports
Machinery & Manufacturing: Shafts, brackets, casings, mechanical components
Vehicles & Transport: Chassis parts, non-critical vehicle structures
Energy & Power: Transmission tower supports, pipelines
Agricultural & Industrial Equipment: Frames, storage tanks, scaffolding
Household & Commercial Goods: Furniture frames, handrails, tubing
Advantages of Q235 Steel Pipes
Balanced Mechanical Properties: Moderate strength, high ductility, good toughness
Excellent Weldability: Low carbon content reduces cracking risk
Versatility: Suitable for a wide range of industrial and structural applications
Cost-Effective: Economical and widely available
Formability: Easy to cut, bend, and machine
Corrosion Resistance: Can be galvanized or coated for enhanced durability
Global Compatibility: Interchangeable with international standards (A36, SS400, S235JR, E250)