Many customers are often confused about the difference between Q235A, Q235B, Q235C, Q235D, and Q235E. Here is a detailed explanation from Gnee Steel.
Grade Classification and Temperature Resistance
The main difference between Q235 grades lies in impact resistance at different temperatures:
| Grade | Minimum Impact Temperature | Impact Characteristics |
|---|---|---|
| Q235A | ≥ +40°C | No impact required |
| Q235B | ≥ +20°C | Impact resistance at 20°C |
| Q235C | ≥ 0°C | Impact resistance at 0°C |
| Q235D | ≥ -20°C | Impact resistance at -20°C |
| Q235E | ≥ -40°C | Impact resistance at -40°C |
Summary:
From Q235A to Q235E, the steel can withstand progressively lower temperatures.
Impact values also vary according to temperature requirements.
Sulfur Content Variation
The sulfur content decreases as the grade moves from A → B → C → D.
Q235A and Q235B: same sulfur content
Q235C: slightly lower sulfur content
Q235D: lowest sulfur content
This adjustment improves low-temperature impact performance.
Chemical Composition
| Grade | C (%) | Mn (%) | Si (%) | S (%) | P (%) |
|---|---|---|---|---|---|
| Q235A | ≤0.22 | ≤1.4 | ≤0.35 | ≤0.050 | ≤0.045 |
| Q235B | ≤0.20 | ≤1.4 | ≤0.35 | ≤0.045 | ≤0.045 |
| Q235C | ≤0.17 | ≤1.4 | ≤0.35 | ≤0.040 | ≤0.040 |
| Q235D | ≤0.17 | ≤1.4 | ≤0.35 | ≤0.035 | ≤0.035 |
Notes:
Lower carbon and sulfur content improve cold temperature toughness.
These grades are commonly used in structural steel, beams, plates, and other low-alloy applications.
