Abstract: A vise adapter for clamping in a bench vise or the like is provided for holding threaded objects. The adapter has a pair of parallel rectangular blocks arranged to slide from a closed position to an open position. The opposing faces of the blocks each have mating threaded essentially semi-cylindrical channels thereacross forming threaded openings when the faces are contiguous. A threaded object is placed in a channel of matching diameter and thread pitch, the blocks closed, and clamped for performing operations on the object.