1.ISO90010:2000 2.Hot dip galvanized steel grating, bar grating, stair treads,Ditch cover , tank grating , pavement grating , Steel Grating,Bar Grating,Ditch Covert, Stair Tread,pavement gratingWe produce ... x 4, etc.2) Bearing Bar Pitch (center to center): 12.5, 15,25, 30, 30.16, 32.5, 34, 40 ...