material:Q235,galvanized load bar:32*5mm cross bar:6mm hole:30*100mm type:T1,T2,T3, ... steel grating production process and by load flat steel bar at certain distances, at high pressure resistance welding machine ... 3 is 60mm.(2) hot dip galvanized steel grating bar center distance: Series 1 100mm, Series 2 is 50mm ... .Common specifications are 20 * 5,25 * 5,25 * 3,32 * 5,32 * 5.40 * 5.40 * 3,50 * 5,65 ...