Thanks to the scored clamping jaws, every pen blank, whether squared, polygonal or round-shaped is fixed firmly and centrally. The clamping jaws open and close symmetrically, which has the advantage that the vice only needs to be aligned centrally on the drill poress table. All subsequent pen blanks, regardless of size, are then always clamped centrally, thus it is no longer necessary to mark the blanks. Maximum clamping diagonal 58 mm.