1.comprehensive type and range in dimension. Flat bearing bar : all range 19X3,19X5,20X3,20X4,20X5,25X3,25X4,25X4.5,25X4.7,25X5,.....40X8,40X10,......90X6,...... Pitch of Bearing Bar(mm):12.5, 15, 20, 30, 30.6, 32.5, 34, 34.8, 35.3, 40, 60, 80...... Pitch of Cross bar(mm): 38.1, 50, 50.8, 70, 75, 80, 100, 101.6, 102...... Material: Mild steel Q235 or other equivalent material Grating Conformity Standard: YB/T4001, ANSI/NAAMM-MBG531, BS4592, AS1657, JS3101 2.Mode: WT1/ST1,WT2/ST2,WT3/ST3,WT4/ST4 WT1:/ST1 used for welding installation, both sides are banded with theflat bars of which the height is same with thebearing flat bars and the thickness is 5mm, without front protection plate. WT2/ST2: used for bolting installation, both sides are banded with 65X5 flat bars and are punched,without front protection plate. WT3/ST3: used for welding installation, both sides are banded with theflat bars of which the height is same with thebearing flat bars and the thickness is 5mm,with a front protection plate of which the thickness is 3mm and the plate is bended and with pattern of lentil shape. WT4/ST4: used for bolting installation, both sides are banded with 65X5 flat bars and are punched,with a front protection plate of which the thickness is 3mm and the plate is bended and with pattern of lentil shape.