Lag Bolt Pilot Hole Size
Unlike screws, which cut their own holes as they’re screwed in, lag bolts require pre-drilled holes to be installed properly. This is to prevent the wood frame from splitting as the lag bolt is screwed in, as well as creating a more secure connection between the materials. It is important that you use a drill bit with the right diameter to ensure the lag bolt goes in deep enough.
The ideal pilot hole size varies by wood type, bolt length and diameter, and the type of materials you’re screwing into. However, for a good general rule of thumb, the unthreaded portion of the lag bolt should have a pilot hole that matches the root diameter (as found printed on the head of the bolt). Similarly, the threaded section of the lag bolt requires a pilot hole that’s larger than the thread size.
In most cases, a lag bolt should be driven into the stud (or wood member) at least twice its own thickness in order to provide adequate holding power. However, it’s always best to consult the documentation included with your specific lag bolt and hardware.
The lag bolt is a robust fastener that’s capable of carrying heavy loads and exerting high shear and tensile forces. When used properly, lag bolts are an excellent choice for fastening wood in framing and construction projects. By ensuring that you’re drilling the correct pilot holes, lubricating your lag bolts, using an appropriate screwdriver and tightening them securely, you can get the most out of this strong, versatile tool. pilot hole for 1/4 lag screw