... ) Hot galvanizing standard: China GB/T13912-925) Wrapping: wrapping is as requested by customers, or depends on the wrappingmethods used ... GradeASTM A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted, spray ... , Australia: AS1657-1985,Germany: DIN24537-1-2006, Japan:JIS steel grating for ceiling grate cover (factory)