Channel steel comes in various standard sizes. The height of the web typically ranges from 50mm to 400mm, with common specifications like 5#, 8#, 10#, 12#, etc. For example, a 10# channel steel has a web height of 100mm, a leg width of 48mm, and a web thickness of 5.3mm. These sizes are designed to meet different load - bearing and structural requirements. Smaller sizes are often used in light - duty structures, such as shelving and simple brackets, while larger sizes are applied in heavy - construction projects like bridges and large industrial buildings. The standardization of sizes ensures compatibility and ease of use in construction and manufacturing.