Each type of wedge anchor is used for different applications, depending on the environment it will be installed in.
The larger the diameter of the wedge anchor, the higher it's cost because the larger diameter contains more steel and is more costly to manufacture. The diameter size also helps determine the holding value; the larger the diameter of wedge anchor then the better the holding values. The diameter of wedge anchor to use can be determined by an engineer or by the diameter of the hole in the material being fastened.
Wedge anchors come in different lengths, with the longer wedge anchors costing increasingly more. Different-length wedge anchors are required to allow for different thickness of material to be fastened to the concrete. The length of the wedge anchor required is determined by adding the minimum embedment for the diameter of wedge anchor being installed plus the thickness of the material being fastened plus space for the nut and washer. The length of the wedge anchor is measured from one end to the other as an overall length, including the threads and the part of the stud that contains the clip.
Wedge anchors are designed to be used in solid concrete only and should never be used in other non-solid base material, such as block (CMU) or block. The design of the wedge anchor creates a mechanical type concrete anchor that has the most consistent and best-holding values of any other type of mechanical concrete fastener. Other concrete fasteners, such as the sleeve anchor, are more versatile in terms of the variety of base material that they can be used in although the holding values are less.
The wedge anchor is described with the first number representing the diameter of the wedge anchor and the second number representing the length of the wedge anchor. A 5/8" x 4-1/2" wedge anchor description means the wedge anchor is 5/8" in diameter with a length of 4-1/2".
The label for wedge anchors used by Concrete Fastening System, Inc. provides the necessary information to determine the type and size of wedge anchors contained in the package. The wedge anchor item number starts with a "WA" which represents "wedge anchor". No other letters will appear for the zinc plated wedge anchor. For a hot-dipped galvanized wedge anchor, a "G" will follow the "WA", i.e. "WAG". If the anchor is standard stainless steel, an "S" will follow the "WA", i.e. "WAS. If the wedge anchor is made from 316 stainless steel, then the part number will have an "S316" after the "WA", i.e. "WAS316". The description then follows the type designation. For example, a zinc plated 5/8" x 3-1/2" wedge anchor's full part number would be WA58312, and the 58312 number would refer to the description of an anchor that is 5/8" x 3-1/2". The label also has a large picture of the wedge anchor, the number of pieces in the box, the type of wedge anchor, i.e. zinc plated, hot-dipped galvanized, stainless steel or 316 stainless steel. The border of the label is also color coded to help distinguish different type of wedge anchors. The zinc plated wedge anchor has a blue border label; hot-dipped galvanized a yellow border label; stainless steel has a green border label; the 316 stainless steel has a red border label.
Wedge anchors come packaged in different quantities depending on the diameter and length of the wedge anchor. The package quantities range from 5 pieces for the large 1-1/4" x 12" diameter to 100 pieces for the 1/4" x 1-3/4" diameter. Each box of wedge anchors comes with the correct number and size of nuts and washers.
The diameter of the hole that must be drilled into the concrete in order to use the wedge anchor equals the diameter of the wedge anchor being installed. A carbide tipped bit that meets ANSI standards must be used to ensure hole tolerance with wedge anchor tolerance. The hole must also be drilled with a hammer drill. The hammer drill must be used in the hammer and rotation mode to ensure that the hole drilled in the concrete will match the hole requirements necessary for the wedge anchor to achieve its holding values.
The hole in the concrete must be drilled a minimum of 1/2" deeper than the wedge anchor will penetrate the concrete. This allows space for any debris created during the installation process to fall to the ground, which will prevent the hindering of the installation of the wedge anchor.
Each diameter of wedge anchor has a minimum depth that the wedge anchor must be installed in order for the wedge anchor to achieve the designated minimum holding values. Check out the technical information page at Concrete Fastening Systems, Inc. for the minimum embedments for each diameter.
Each diameter of wedge anchor needs to be torqued to ensure proper installation. Two or three full rotations of the nut will usually meet the requirements. However, if a torque wrench is available then torque the wedge anchors to the designated torque value for the diameter of wedge anchor being installed.
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.