Roofing bolt 1.Bolt Size,M5-M20 2.Material,stainless steel,carbon steel 3.SGS,ISO 4.Zinc or Nickel plated,Black Oxide ... or non-standard as request&design.2. Material:Carbon steel, Alloy steel, stainless steel or according require.3. Grade of Roofing bolt:Metric ... .9,Grade12.9.Inch standard: Grade2, Grade5, Grade8, B7.stainless steel , A2-70, A4-70, A4-804. Dimension : M5-M20 or ...