A specialized, high-performance roofing fastener designed to secure insulation and single-ply membrane to steel, O.S.B., or aluminum roof decks. Drill-Tec™ XHD® #15 Fasteners have an over-sized heavy shank and thread diameters for enhanced pull-out resistance in steel and aluminum roof decks to secure insulation and single-ply membrane to steel, O.S.B., or aluminum roof decks.