Twisted Shank Nails Iron or steel wore, flat head, throughout twisted(square section or flutes) shank, diamond point. Iron or Steel wire Flat Head Twisted Shank NailsIron or steel wore, flat head, throughout twisted(square section or flutes) shank, diamond point. Available: bright, E.G.,C.C., V.C., H.,D.G..and P.C. finish. Iron or Steel wire Flat Head Twisted Shank Nails