duplex nail 1.shank shape : screw , smooth , ring 2.diameter : 5 gauge to 20gauge 3.size : 1"4" duplex nail1Material of nail Low and middle –carbon steel ,Q 195 Q 2352Surface treatmentPolished , galvanized , electro-galvanized with zinc and electro-galvanized color zinc , balck blue , yellow ,mechanical galvanized ,bright3StandardCan be made according to different standards : ISO ,GB , ANSI , BS ...