A power impact tool adapter, for use in installing a bit to be used in a striking-motion-deactivated mode to a power impact tool, includes an SDS type shank portion to be held by a chuck; closed grooves to be mated with sprung balls to prevent the release of the bit; and slide grooves to be slidably mated with wedges applying a rotational force to the bit. An axial length of each slide groove is shorter than that of a slide groove of a standard SDS shank such that the end of the shank portion is prevented from contacting a striking member of the power impact tool which applies a striking force to the bit.