When it comes to building things there are many types of fasteners you can use. Bolts, screws and rivets are just some of the choices available to fasten materials together. For projects that require an intense load-bearing connection, lag bolts can provide an extremely strong and durable connection.
Also known as lag screws, these heavy duty fasteners are used for wood construction and can be found in a variety of home improvement projects. They are often used to lag lumber framing together, attach machinery feet and other such heavy carpentry applications. When used in place of nails, lag screws can hold up to nine times more weight than a basic nail driven into a stud.
A key difference between lag bolts and other types of screws is their pointed end, or hex head. This point allows the hex head to get into tight spaces and provides extra strength when using a wrench. The head is typically forged which is the process of heating a round steel rod and using an upsetter to forge it into the proper shape, usually hex or square. Lag bolts are also tempered to give them increased resistance to shear and impact damage.
Before installing a lag screw, it is important to pre-drill the hole you are going to use it in. This step is especially crucial when using a drill/impact driver since lag bolts do not have the benefit of self-drilling like screws. It is recommended to use a drill bit that is slightly smaller in diameter than the actual lag bolt to ensure the threads have sufficient material to bind to.