Wedge anchor is the description for a concrete anchor that is a one piece, non-bottom bearing concrete anchor that is threaded on one end and has a steel clip at the other end. They are packaged with a corresponding number of nuts and washers are designed for use in solid concrete. The wedge anchor has the best and most consistent holding value of any mechanical type concrete fastener. Wedge anchors can be used in concrete only and will not work in other base materials such as brick or block.
Wedge anchors are manufactured in a wide variety of materials that meet the majority of application requirements. It is a good choice for indoor use and in environments where no moisture is present. Hot-dipped galvanized wedge anchors are used in outdoor applications where moisture and no chemicals are present. They are acceptable for use with treated lumber as well. Stainless steel wedge anchors are manufactured in both 303 and 316 stainless steel for use in water and other caustic environments. While many companies sell this type of product under their own brand names, such as the Hilti Kwik Bolt and Powers Power Bolt®, Concrete Fastening Systems is the only company still selling this product as wedge anchors.
The process for installing wedge anchors is described below:
1. Drill a hole in the concrete using a carbide bit and a hammer drill. The diameter of the carbide bit is the same diameter as the anchor being used. Make sure the carbide bit meets ANSI standards B212.15 to ensure proper hole size for the anchor. The hole needs to be drilled to a depth a minimum of one anchor deeper or 1/2" deeper than the wedge anchor will penetrate. This will allow space for debris to fall during the installation process. The fixture can be used for a template but make sure that the holes in the fixture are large enough for the drill bit to fit through.
2. Before inserting the wedge anchor, it is important to clean any debris from the hole using a wire brush, vacuum or compressed air. This step is taken to ensure that the hole is clean of any debris. This is critical for a successful anchor installation.
3. Put the washer on the wedge anchor can thread the nut on. It is important to make sure that the nut is threaded so that the top of it is level with the top of the wedge anchor in order to help protect the threads from any damage while hammering the anchor into the hole.
4. Insert the wedge anchor (with the clip end first) through the fixture or directly into the hole in the concrete. Using a hammer, hit the wedge anchor and nut with sharp blows until the washer and nut are snug against the base material or fixture. It is critical that there is a minimum of 6 threads below the surface of the concrete or the fixture because these threads will be required to set the wedge anchor.
5. Tighten the nut finger tight and then take a wrench and turn the nut 3-5 times to the recommended installation torque. This pulls the wedge anchor up, wedging the clip between the steel stud and the wall of the hole in the concrete.
Wedge anchors are an excellent choice when fastening into solid concrete. By following the instructions above, installation of these fasteners should be successful.
As with any anchoring project, it is important to keep safety in mind and follow instructions carefully. Always remember to wear safety goggles, handle all tools with extra care and follow all technical specifications. This article is meant to serve only as a basic explanation of concrete fasteners. Always refer to manufacturer's instructions or consult a contracting expert during any anchoring project.