SatelliteSale General Purpose 5/16" Outer Diameter Hex Head Lag Bolt Zinc Plated Screws are specially produced and designed for wood and concrete installations, making them perfect for your roof, wall, or decks. It can be used for indoor applications and projects as well. Zinc plated material grants oxidation resistance and grade 5 metal provides increased durability. Usually installed in tripod feet, satellite mount feet, antenna base, and mast or other mounts that penetrate roof or mooting surface, but might come in-handy in similar building projects. The screw features anti-reversing teeth under the cap washer for your convenient installation. Keep in mind that hardwoods should always be pre-drilled with a pilot hole, so our Lag Screw can be installed. In order to screw-in SatelliteSale lag bolts, we recommend using hex head drive 7/16". We assure the lifetime service of lag screws to deliver a positive experience to our clients.