Compound steel grating 

     1. Combined steel grating refers to a product composed of steel grating with certain spanning capability and chequered plate on sealed surface.
     2. Combined steel grating is composed of any type of steel grating and checkered plate in different thicknesses. The checkered plate with 3mm thickness is normally used, and the plate of 4mm, 5mm or 6mm thickness may also be used.      
     3. Hot dip galvanization treatment