... grating is made of flat steel according to certain spacing and cross bar (twisted square steel, square steel, round steel, flat ... steel, etc.) to cross arranged, and welded into the middle with square lattice, is a kind ... , 40X8, 40X10,….90X6….Pitch of Load bearding flat bars(mm)12.5,15, 20, 30, 30.6, 32.5, 34, 34 ...