Q345B and Q355B are low-alloy, high-strength structural steels widely used for H-Beams in construction, bridges, heavy machinery, and industrial structures.
Q355B is a newer grade under GB/T1591-2018, equivalent to Q345B from GB/T1591-2008, and also comparable to S355JR in EN 10025-2:2004.
| Q345B | 0.20 | 0.50 | 1.70 | 0.035 | 0.035 | 0.30 | 0.50 | 0.30 | 0.012 | 0.07 | 0.15 | 0.20 | 0.10 |
| Q355B | 0.20 | 0.55 | 1.60 | 0.030 | 0.030 | 0.30 | 0.30 | 0.40 | 0.012 | - | - | - | - |
| Q345B | Q355B | |
|---|---|---|
| <=16 | >=345 | >=355 |
| 16–40 | >=335 | >=345 |
| 40–63 | >=325 | >=335 |
| 63–80 | >=315 | >=325 |
| 80–100 | >=305 | >=315 |
| 100–150 | >=285 | >=295 |
| 150–200 | >=275 | >=285 |
| 200–250 | >=265 | >=275 |
| 250–400 | - | - |
| Q345B | Q355B | |
|---|---|---|
| <=40 | 470–630 | 470–630 |
| 40–63 | 470–630 | 470–630 |
| 63–80 | 470–630 | 470–630 |
| 80–100 | 470–630 | 470–630 |
| 100–150 | 450–600 | 450–600 |
| 150–250 | 450–600 | 450–600 |
| 250–400 | - | - |
Q345B and Q355B H-Beams are used in:
Gnee Steel supplies both Q345B and Q355B H-Beams with custom sizes and further processing services. Inquiries for Q345B or Q355B H-Beam pricing are welcome.
