First of all, the first "G" represents the steel grating plate, 305 represents the bearing flat steel 30mm*5.0mm, 30mm represents the height of the bearing flat steel, 5.0mm represents the thickness of the bearing flat steel, "30" represents the bearing flat steel spacing 30mm, "100" represents the twisted steel spacing 100mm, "W" represents the welded or pressure welded steel grating plate, which can be omitted in the marking. "F" stands for plain flat steel, and "G" on the last edge stands for hot dip galvanizing.
Below are some letters commonly used in steel grating plate:
Steel grating plate marking: W- welding or pressure welding steel lattice, L- pressure locking steel lattice means, load flat shape marking is: F- ordinary flat, I- is I type flat, S- is tooth line flat.
Marks for surface treatment status: G- means hot-dip galvanizing, P- means paint, and U- means no treatment.