What is the ideal pilot hole size for a lag bolt?
Lag bolts, also known as hex screws or lag screws, are a type of fastener that is screwed into wood. They have a hex head and a cylindrical shaft that has smooth and threaded parts. Lag bolts are used to connect or fasten wood or metal and are available in both domestic and imported varieties. When installing lag bolts, it’s important to predrill the holes where they will be inserted in order to prevent splitting the wood or damaging the bolt’s threaded end. Lag bolts can be driven into wood or metal with a standard manual drill, power drill or electric screwdriver. In addition, lubrication may be necessary to ease installation and ensure a proper seal.
To determine the appropriate pilot hole size, start by finding out the root diameter of your lag bolt. This information can usually be found printed on the bolt box or by using a ruler to measure from the bottom of the head to the threaded tip. Next, find the corresponding number on our Lag Bolt Pilot Hole Size Chart and select the correct drill bit to match.
Keep in mind that a number of factors will impact the ideal hole size, such as wood species and bolt length. It’s always best to consult a professional or review local building codes if you are uncertain about what size to use. For example, a 3/8 inch lag bolt should penetrate the material by at least five diameters of its own threads in order to provide adequate strength and support. pilot hole for 5/16 lag screw