Wood Screw Threaded Metal Anchor Zinc 1/4-20 * 1-1/2"

Also known as lag shields, these anchors are designed to be used with large-diameter wood screws. They reinforce the hole and resist stripping. Each diameter is available in two lengths. The shorter length reduces drilling time: the longer length provides more strength. To install, tap into a drilled hole with a hammer and position your fixture. Then, insert a lag screw and tighten. Install flush or slightly below the surface. Pull-out strength and shear strength values are 25% of the ultimate values.