The CONFAST single expansion anchors are designed for anchoring into concrete, brick or block base material. This light to medium-duty fastener is a non-rusting material, and is available in diameters ranging from 1/4 to 3/4 inch. The single expansion anchor is set flush with the base material and inserting a machine-threaded bolt into the anchor expands it against the concrete at a single point. Considerations when using the single expansion anchor include anchor diameter, bolt diameter and required hole size. The single expansion anchor is an effective fastener when working with soft masonry or base materials of questionable strength. Anchor size refers to the diameter of the machine bolt/screw used to expand this anchor. For more information, visit