Concrete Single Expansion Anchors are designed for anchoring into concrete, brick or block. Inserting a machine-threaded bolt expands the Single Expansion Anchor against the the concrete at a single expansion point. The single expansion anchor can be used in concrete, brick or block base material. It is made from of a non-rusting material and comes in diameters 1/4" to 3/4". The single expansion anchor sets flush in the base material and is considered a light to medium duty fastener.