A lag bolt, also known as a lag screw, is a large wood screw with a hexagonal head that is used to connect heavy lumber or other heavy materials that are bearing an intense load. Lag bolts are different from normal wood, self-drilling, or sheet metal screws because they are massive in size, with most being at least one inch long and ¼-inch thick. They have a sharp gimlet point and coarse threads for maximum holding force in wood, but due to their large diameter, they must be predrilled. Lag screws are installed by rotating the head to screw the lag screw into the wood, and they do not require nuts to secure them in place. Lag screws are used for intense load applications and can support a much heavier load than the average sheet metal or wood screw. They are commonly used for roof beams, garage pillars, TV wall mounting, and heavy construction. To install lag screws, the first step is to make sure that all of the materials involved in the application are aligned. Once everything is secure, drill a pilot hole using a bit with a slightly smaller diameter than the lag screw that will be used. When drilling the hole, make sure to drill all the way through the area where the screw will eventually be. Lag screws are only available with hex heads, and installation of the screw will require a nut driver or ratchet.