Double expansion anchors are designed for anchoring into concrete, brick or block base material. Inserting a machine-threaded bolt into the anchor expands the Double Expansion Anchor against the concrete at two points. It is made from Zamac, a non-rusting material, and is available in diameters ranging from 1/4" to 3/4". The double expansion anchor is set flush with the base material and is considered a light to a medium-duty fastener. The double expansion allows for better holding values.
- The CONFAST® double anchor is an expansion anchor suitable for use in a variety of masonry base materials, such as brick, block or concrete.
- The double anchor is a female type anchor that requires a bolt that is sold separately and works to expand the anchor once it is placed in the hole.
- The CONFAST® double anchor works well in base material that is suspect in terms of its quality, i.e. soft or sandy, because it expands upon its entire length. This provides the maximum opportunity for adequate friction, thus increasing the chances for obtaining minimum holding power.
- It is important to remember that the holding value is only as good as the base material into which the anchor is placed.
- First, a hole must be drilled in the concrete utilizing a hammer drill set in the hammer and rotation mode and using a carbide tipped bit that meets ANSI standards.
- The hole must be equal to the outside diameter of the CONFAST® double anchor being installed, noting that each diameter requires a different size hole. The designated diameter of the anchor is equal to the inside diameter, or bolt diameter.
- The hole must be drilled a minimum depth equal to the length of the CONFAST® double anchor, making sure that the anchor is even or below the surface of the base material.
- Once the hole has been drilled, place the CONFAST® double anchor in the hole using a slight tap with a hammer to allow placement.
- Place the item over the anchor, then insert the screw and turn to expand the anchor.
- Holding values of the CONFAST® double anchor vary depending on the type and quality of the base material. Therefore, each anchor may have different holding values.
- To obtain minimum holding values, the CONFAST® double anchor must be placed in the base material the length of the anchor and with the anchor fully expanded.
- The threads of the bolt required for the CONFAST® double anchor must be national coarse threads.
- The CONFAST® double anchor are available in six different diameters; each diameter is manufactured in just one length.
- The required national coarse threaded bolt is the second number in the description, and refers to the number of threads per inch: 1/4"- 20, 5/16" - 18, 3/8" -16, 1/2" – 13, 5/8" – 11, and 3/4" – 10.
- The quantity in each box of CONFAST® double anchor differs based on size, with the larger size packaged with fewer anchors in the box.