Specifications: 1)Size: M3-M30 2)Material: Carbon Steel and Alloy Steel 3)Plating: Black Oxide,Zinc, Specifications:nut1)Size: M3-M302)Material: Carbon Steel and Alloy Steel3)Plating: Black Oxide,Zinc, Chrome, Galvanized,Nickle, Dacromet, Delta-Tone, Geomet,Ruspert4)Grade: 4, 6, 8, 10