SRD's Roofing Screws fasten single-ply roofing materials to heavy-duty steel, wood, and structural concrete roofs. Its enlarged heavy-duty screw and thread diameter increases the pull-out resistance on light steel roofing and aluminum roofing base, and the deeper serrated thread further enhances the pull-out resistance; the micro drill quickly penetrates the sheet and can also improve the resistance against withdrawal and pull-out is significantly enhanced.