A lag bolt is among the toughest types of fasteners in construction, used to connect heavy lumber and other materials that bear intense load. They are not to be confused with other screws like wood or self-drilling screws that have a threaded exterior. While most lag bolts have a hex head, they do not accept a nut and are installed by rotating the screw itself. They have up to nine times more grip in a stud than a basic nail hammered into the same stud and can support much more weight than a regular wood screw.
Lag bolts have coarse, sharp threading that only covers a portion of the shaft and feature a hex or square head that can be turned by a wrench or socket. They are typically made of steel and come in a variety of lengths, but they can also be made from brass, silicon bronze, or hot-dipped galvanized steel to meet specific project requirements.
When using a lag bolt, the first step is to confirm that the materials being fastened are properly aligned and use clamps to keep them in place. Then, a pilot hole should be drilled into the material with a bit that is slightly smaller than the diameter of the lag screw you are using to ensure that the bolt has enough space to bind in place.
Lag bolts have a protruding head that can be unsightly and even present a potential hazard in some projects, so it’s important to drill countersink holes into the materials you are working with before installing them. To do this, you can use a large spade drill bit to create a countersink hole in the pre-drilled pilot holes that is a little larger than the diameter of the lag bolt head. This will help to hide the head of the bolt and ensure that it’s tightened properly. lag bolt