CONFAST Double Expansion Anchor

The CONFAST double expansion anchors are designed for anchoring into concrete, brick or block base material. The double expansion anchor is great for projects where the base material is soft or has strength that is suspect.
Double expansion anchors are designed for anchoring into concrete, brick or block base material. The anchor body is made from a die cast alloy called Zamac, which is rust resistant and extremely durable. It has two expansion cones: one cone is threaded and the other is not. Two spring steel bands wrap the two halves together and allow the anchor to expand against the concrete at two points to allow for better holding values once installed.

Tips for Using the Double Expansion Anchor
Designated Diameter / Hole Diameter
1/4” ½”
5/16” 5/8”
3/8” 5/8”
1/2” 7/8”
5/8” 1”
3/4” 1-1/4”


· The length of the bolt that should be used for all installations of the anchor is equal to the thickness of the material being fastened plus the depth the anchor will be embedded.
· It is important to note that one end of the double expansion anchor has a nut that is threaded. When installing it, hold the opposite end or the end with the nut that is not threaded and insert the threaded nut end into the hole first. Tap lightly with a hammer if needed until the anchor is flush with the surface of the base material.
· Take the fixture being fastened and align the holes in the fixture with the double in the base material.
· Insert the national threaded bolt through the fixture and into the anchor. Turn the bolt clockwise until the anchor is fully set. Do not over torque the bolt since this may cause the double expansion anchor to spin in the hole and lose its holding strength.