... plated / Yellow zinc plated / Plain 3)Usage : Carbon steel /4)Size:M4-M80 or customer require 1. Standard:DIN ... non-standard as request&design.2. Material:Carbon steel,3. Grade of hex bolt and nut:Metric standard ... ,Grade12.9.Inch standard: Grade2, Grade5, Grade8, B7.stainless steel , A2-70, A4-70, A4-804. Dimension :Metric ... % advance and 70% after B/L copy GALVANIZED MILD STEEL ROOFING hex bolt and nut