Detailed Product Description hex nutSize: M4-M56, 2#-2-1/4 Standard: DIN934 Material: Lowcarbon steel, middle carbon steel, alloy steel, stainless steel, aluminum, brass Grade: 2, 5, 8, 10, 2H, DH Class; 4, 5, 6, 8, 10, 12 Surface: Zinc plated(yellow, black, green), black oxide, nickel plated, chrome plated, Cr+3, hot dip galvanized, brass plated