Foot thickness means that the actual thickness is not much different from the theoretical thickness (also called label thickness), which is a small negative difference. If the label thickness is 1.0MM, the general required foot thickness is at least about 0.98MM-1.0MM, and the foot thickness can be It is understood as "thick enough", and the standard thickness is the theoretical thickness. The coils of the steel mill are labelled when they leave the factory, indicating the theoretical thickness. This is the standard thickness.