Duplex head nails description: Double headed, smooth shank, diamond shank, bright finish. Duplex head nails application: Duplex head nails are used for temporary construction, such as form work or scaffolding. The double head on this nail makes it easy to pull out when forms or scaffolding are torn down. Duplex Head Nails Size: BWG supplies quality roofing nails for binding of drywall to wood to secure the shingles. Technical Info: Nail Head Size(mm): 14mm/18mm/20mm/24mm Head Type: Umbrella head, flat head Roofing Nails Shank Type: Smooth shank, twisted shank Finish: Galvanized, hot dipped Specification: 1-1/2 x BWG8-BWG13 1-3/4 x BWG8-BWG13 2x BWG8-BWG13 2-1/2x BWG8-BWG11 1-1/2" - 3" x BWG 5-13 Packing: In carton of 20kg-25kg net each. Or in wooden case of 112lbs each, consisting of 16packets x 7lbs net each.