How to Install Lag Bolts

When you’re working on home improvement projects or major construction work, you may need to secure heavy-duty materials using fasteners like lag bolts. These types of bolts have a lot in common with screws, but they’re able to handle much more force than typical screw-type fasteners.

The difference is primarily in the heads and threading of the bolts. While most screws have a smooth head, lag bolts have a hex or square-shaped heads that are designed to fit a wrench. This makes them easier to grip when installing or removing the bolts.

Additionally, lag bolts’ threading extends much further down the shaft than most screw-type fasteners. This allows them to support greater loads and hold tighter, especially when they’re used in thicker wood. The increased strength that lag bolts offer over screws also means that they’re best for use in applications that require more than just simple wood-to-wood connections.

A lag bolt can be used in any type of wood, but they’re particularly suited for larger size lumber and are often used to fasten outdoor stairs and landings. They’re also frequently used to secure beams, retaining walls and other major structures. The word “lag” in this case actually refers to the way these bolts were originally made, as they were used to secure barrel staves and other large pieces of wood.

Lag bolts are easy to install, but they do need to be pre-drilled so that their threads have a good connection with the material into which they’re being installed. Using a drill bit that’s a little smaller than the diameter of the bolt is recommended. This will prevent the bolt from drilling into and damaging the underlying wood or application surface.

Once the hole has been pre-drilled, a lag bolt can be driven in with a ratchet or other tool. It’s important to be careful not to over-tighten the bolt, as this can cause it to strip or even snap off its head. It’s also a good idea to use washers with lag bolts. This will increase the number of contact points and spread out the driving torque to avoid damage to the wood or application surface.

While a lag bolt can be driven in by hand, it’s usually preferable to use a ratchet or other tool to apply the final torque. This will ensure that the bolt is properly tightened and can withstand the stresses of a construction project. In some cases, it’s also a good idea to use a thread locker on the bolts, as this can help them resist the effects of vibration and movement that could otherwise loosen them over time.