A double expansion anchor is a type of masonry anchor used for anchoring into materials of questionable strength or quality. In the world of masonry anchors, most rely on deforming a portion near the bottom of the anchor once inside a hole to prevent the anchor from coming loose.
Double expansion anchors differ from other?masonry anchors. Instead of the bottom portion of the anchor expanding dramatically to create a strong grip, the entire anchor expands, but only slightly, in size to distribute the pressure over the entire surface area of the anchor.
To install a double expansion anchor, follow the steps below:
1.Using an?SDS drill bit, drill a hole into the brick the same diameter as the anchor. The hole will need to be slightly longer than the anchor in-depth.
2.After cleaning out and debris from the hole, insert the double expansion anchor into the hole with the threaded portion near the bottom.
3.Next drill a hole through the material that will be anchored to the brick.
4.Line up the holes and use a matching machine screw to catch the threads of the anchor. The initial spins can be done by hand.
5.Using a screwdriver, tighten the machine screw until it tightens against the surface of the material being connected to the brick. *Note: The length of the machine screw will vary depending on what you are attaching to the brick.
One of the unique things about double expansion anchors is that they can be easily removed from an installation hole and reused. To remove one simply take out the machine screw and it will form back into its original shape. Then it can be removed from the hole.