Most anchors for use in hardened concrete rely on torquing to secure them and establish their holding strength. Clumsy, time-consuming complications may ensue as one must pound the anchors into a predrilled hole and then change tools to tighten and set the anchor. The new anchor described here differs from such torque type anchors. Installation is achieved with a single tool: by striking the center wedge pin with a hammer or rotohammer. The action causes legs at the base of the anchor to expand, creating a constant wedging force. Achievement of predictable and consistent tensile strengths does not depend on the installer's strength as do torque-secured anchors. The required depth is obtained by presetting the nut and washer to a predetermined location on the bolt. This feature makes it possible to select either a flush head or stud for the same anchor. Since the center pin creates the locking force, the nut and washer are not needed after installation to maintain anchorage of the bolt to the concrete and they can be removed. This makes it possible to remove a machine or other component and set an identical one is its place. The anchors may be set either before or after the machine or other component is set.