Abstract: An anchor bolt with a pair of expansible limbs on its leading end in spaced-apart relation separated by a diametric slot therebetween is adapted for being driven into engagement with the walls of a blind hole and includes a wedge member in the slot between said limbs for forcibly expanding the limbs into engagement with the walls of said hole and an indicator means for visually determining whether the limbs have been properly expanded in the hole. In the preferred embodiment, the visual means is comprised of an elongated finger extending rearwardly from the wedge member through an axial bore into the head of the bolt on its trailing end, and in an alternate embodiment, a pair of spaced-apart fingers extend rearwardly in respective grooves alongside the shank of the bolt to the inside edge of the head.