... airport, parking, highway, railway, industrial engineering and so on.Type of bearing barW--welded steel grating L-- pressure-locked C ... 30/100 WFG 1.CERTIFICATE : ISO 9001:2008 quality system certificate INTRODUCTION TO COMMON STEEL GRATINGS: Bearing bar centers ... Belt corridor, storage shelf,Attic panel, trestle, guardrail, sunshade gate, etc. common welding standard: single-side full welding every ...