hot-dip galvanized steel grating material: Q235,Q255,Q305, ... 3 percent, more than twice of cast iron products. Hot-dip galvanized treatment: Good rust-proof property, maintenance-free ... ,32x5,40x5,50x5,.....75x10mm2Bear bar pitch12.5, 15, 20, 23.85, 25, 30, 30.16, 30.3, 34.3 ... /NAAMM(MBG531-88)UK: BS4592-1987Australia: AS1657-1985 23)HOT SELL!hot dipped galvanized steel grating manufacturer (10 years )