When specifying thickness of webs/flanges for built-up sections, or specifying base plate thicknesses, there are standard sizes which we would stick to depending on the practice of the local region. We outline some examples below.
Standard plate sizes in UK
A list of standard plate sizes used in the UK is shown below:
| 6 | 22.5 | 45 |
| 8 | 25 | 50 |
| 10 | 30 | 55 |
| 12.5 | 32 | 60 |
| 15 | 35 | 65 |
| 20 | 40 | 70 |
Standard plate sizes in Japan
A list of standard plate sizes used in Japan are shown below:
| 2.3 | 16.0 | 42.0 |
| 3.2 | 19.0 | |
| 4.5 | 22.0 | |
| 6.0 | 25.0 | |
| 9.0 | 28.0 | |
| 12.0 | 32.0 |
Other Considerations
Note that there is generally a reduced minimum yield strength when selecting thicker steel sizes. For example, a S355 steel section which is 25 mm thick will have a yield strength of 345 N/mm2. However, the same steel grade with 45 mm thickness will have a minimum yield strength of 335 N/mm2.
Also, be mindful of minimum steel thicknesses for certain elements. For examples, in the UK minimum base plate thicknesses are typically 15 mm, whilst in Japan they are 16 mm. In general, avoid plate thicknesses above 40 mm except in exceptional cases.