About Lag Bolt Pilot Hole Size
Like wood screws, lag bolts are screwed into materials with a drill, but unlike them, they do not cut their own holes. Instead, they rely on a pre-drilled pilot hole to screw into the material and they require the use of hex wrenches instead of regular screwdrivers. Lag bolts are designed to securely fasten materials together such as studs and plates without weakening the integrity of the material. Getting the correct size pilot hole for a lag screw is critical to ensure the bolt will penetrate into the material and create a strong hold.
Generally, a lag bolt should penetrate into the material by at least two diameters of its thread length for an adequate hold. There are a number of variables that can change the required pilot hole size, such as the bolt diameter and length, the type of wood being used, and the density of the material. It is always best to consult with a professional or review local building codes when determining the appropriate lag bolt penetration for a particular application.
Using the right sized pilot hole for a lag screw will make it easier to install them in a variety of applications and materials. Properly lubricating lag bolts during installation can also help to improve their performance. Beeswax and paraffin wax are commonly used, although bar soap can be an effective alternative. Be sure to use a product that is non-glycerol based, however, since products that contain glycerin will accelerate the rate of bolt corrosion (see article on Lag Bolt Corrosion for more information). Having the proper tools and safety gear in hand when working with lag bolts can help to ensure a successful project. pilot hole for 3/8 lag screw