operator in a large volume manufacturing process where the work stock and the machining operations are the same for each work product produced automation is of course more efficient where the attraction force is to vary in accordance with the weight of the core a look up table may be utilized to control the degree of magnetization based upon the calculated or input weight of the core also an attraction force profile may be used under processor control that gradually builds up the attraction of the core to the magnet thus precluding too great of a force being applied to the core before the machining is completed since the workpiece could be damaged if the core is removed too rapidly these and other process considerations could be achieved well within the capabilities of one of ordinary skill in the art it will be appreciated that permanent magnets may be used as attracting means instead of the electromagnets in the preferred embodiment a controller may be used to control the degree of energization of the coils of electromagnets for control of the magnetism thereof so as to vary the attraction in accordance with the weight of the workpiece it will be appreciated that rare earth alloy permanent magnets e g iron chrome cobalt alloy magnets and samarium cobalt alloy magnets may be employed as permanent magnets instead of commonly used alnico or ferrite magnets it will also be appreciated that suction may be utilized to attract the cores instead of the magnets employed in the preferred embodiments of the invention it will.