Metal attachment for fitting in solid material such as concrete, natural stone, full tiling and stone. When the expansion nail is hammered into a pre-drilled hole, it compresses, springs out and expands along the entire nail length Easy to fit. Easy to use when fitting joists, sills, roofing irons, holed steel banding and piping suspension in concrete. Specially suitable for fixing wooden joists, blind jambs around windows and infill sections with narrow edge distances. Fitting instructions: Drill a hole adapted to the size of the expansion nail and hammer home the nail. The parallel expansion along the entire nail length gives a proper mating union to the substrate which in turn gives a strong and safe fastening. Made from tempered spring steel. Galvanized.