... plusnutspecification: M3-M12material: steelzinc plated: colorful , white and blue ,blacktype: body with open notch, head with notchwe use cold forged technique ... fittings of industrial products. types: flat head ,countersunk head, round body, hex body, open end, closed end, body with ribben, body with groove and so on ... /16,3/8 . material: steel, stainless steel, brass,aluminium notch plus nut