6 Metal threaded fasteners; metal screws, metal nails, metal bolts, metal plates, metal anchors, metal rivets, and metal washers; metal bars used to secure metal threaded screws assembled in plastic lock plates; metal bars used to end single-ply membranes to parapet walls and other penetrations; nails that feature caps that are pre-assembled with fasteners and are used to affix material to plywood; metal strainers for restricting passage of twigs, leaves or other non-liquid foreign matter into roof drains; roof drains, roof drain insert couplings and roof drains for retrofit roofing made of metal; roof drain attachments, namely, plate-bracket attachments made of metal for increasing water flow rate