... 1 1/4''x1/8'', 1 1/2''x1/8'' etc 2Bearing Bar Pitch12.5, 15, 20, 23.85, 25 ... , 11-w-4, 19-w-2, 15-w-2 etc. 3Twisted Cross Bar Pitch38.1, 50, 60, 76, 80 ... 120mm, 2'' & 4'' etc 4Material GradeASTM A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, ... : AS1657-1985,Germany: DIN24537-1-2006, Japan:JIS steel grating for ceiling grate cover (factory)