... galvanized steel stair tread, steel stair treads, serrated, plain, I bar , ISO9001 CMPY, GRATING SPECIALIST, Mr.David galvanized steel stair ... Style Steel Grating, Serrated Style Steel Grating and I Bar Type Steel Grating. They are widely used in steel structure ... . David Huang) 6Grating StylePlain / Smooth, Serrated /teeth, I bar, serrated I bar (Mr. David Huang) 7StandardChina: YB/T 4001.1-2007 ...