4 Tips for Drilling a Lag Screw

A lag screw is the poor man's concrete anchor. The lag screw is used in a myriad of materials to create structural integrity where it is needed most. Once the lag screw is installed, it takes a brunt of the weight and removes it from the structure. You'll often see lag screws on patios, porch swings and entertainment centers. Lag screws are thicker than ordinary screws and have a hexagonal head. The following information will help you with tips so that using a lag screw is not so difficult.

1. Always use a Pilot Hole

A pilot hole is a hole that is drilled into the material you wish to use a lag screw on. The pilot hole serves as a guide for the screw which prevents it from going off course or splintering the material it is being installed in. If you do not use a pilot hole with a lag screw, you will find that they tend to go in crooked, which can prevent them from doing their job. Drill a hole into the material that is smaller than the diameter of the lag screw. The smaller the pilot hole the more effective the lag screw will be. You also do not have to go very deep. A good rule is to drill your pilot hole 1/3 of the length of the screw. This will suffice as a guide for the lag screw.

2. Measure

When working with a material, you should never use lag screws that are not proportionate with it. You not want to use a lag screw that is 8 inches in length with materials that total 7 inches in thickness. Always measure the materials that are meant to be joined. The length of the lag screws used should not be more than half the total thickness of the materials being joined together. If your material totals 10 inches thick, then using a lag screw that is 5 inches long will be more than adequate for your needs. You may use slightly longer screws if the finished project will be subject to more than normal weight or use. The thickness of the lag screws also matters. If they are too thick they can easily splinter the material.

3. Use the Right Tool

Lag screws are not installed in the traditional sense. You need to first use a drill to make a pilot hole in the material and then an electric screwdriver or drill with the proper attachment. The hexagonal head of lag screws means you will need a hexagonal bit in order to install them, tighten them or remove them. Using pliers or a wrench can get the job done, but it will never be as secure as it would be using a powered device.

4. Punch It In

This doesn't mean use a hammer, but refers to how you actually install the lag screw. Most other screw types can be installed slowly. A lag screw, however, is best installed in one quick burst. This prevents the screw from wobbling and splintering the wood.