Fischer Wall Plugs Nail plug 614683 - Fischer 513840, The Fischer nail plug 513840 is a durable fastening solution, 40 mm in length and 6 mm in diameter. It is typically used for secure fastening in solid materials like concrete or masonry. This product is particularly useful in construction and building applications, providing a reliable hold. Fischer 513840 Nail Plug Set 100pcs polyamide zinc-coated screw