... 30, 40, 60, 80, 90 mm etc. with 30, 40 mm recommended.Cross bar centersany greater ... than 30mm is ok. with 50, 100mm recommended. Surface treatmentG-hot-dip ... grating is the most commonly used in projects with American, Australian, Japan standards are available. This ... well resistance of strong impact on surface. Gratings with cross bar centers at 50mm can bear lateral ...