Start the installation by drilling the hole. The depth should be at least equal to the length of the lag shield you will install, but with a diameter that is larger than the designated size of the lag shield anchor. For example, a 3/4” lag shield requires a 1” hole. Use a vacuum to clear the hole of all dust and debris. Then, clean the hole with a wire brush that has the same diameter as the hole.
The length of the lag screw requires you to add the thickness of the material you will fasten to the length of the anchor and the thickness of any washers. You can embed a long lag shield, as compared to a short shield, deeper into the base than the required minimum, if you would like to achieve a higher holding value. Use the depth gauge on your hammer drill to determine the correct depth of the hole.
Next, hold open the end of the shield and insert the closed end into the hole. With a slight tap of the hammer, set the lag anchor flush to the surface of the base material. Line up the holes on the fixture (item to be fastened), with the shield and insert the correct-length screw through the fixture and into the lag shield. Tighten by hand.
With a wrench, turn the lag screw counterclockwise until it’s tight against the surface of the item being fastened. Be careful not to use too much torque on the screw, because it may cause the shield to spin in the opening and lose its holding value.