... ' requirement 4.ISO Galvanized stair tread are made from steel gratings and other forms. They are widely used Inner packing: municipal ... bar pitch: 12.5, 15, 20, 23.85, 25, 30, 30.16, 30.3, 32.5, 35, 40mm. US standard: 1"x3/16 ... 1/4" etc.3. Cross bar pitch: 38,50,76,100,101.6mm4. Material: Q235, Stainless 3045. Surface treatment: black, galvanized ...