a mechanical apparatus and tool for clearing small areas of the plastic film insulation in flat flexible circuits and cables to permit making electrical connections to the metal foil conductors . an end - mill - like rotating cutter is fed into the laminated workpiece . novel cutter geometry provides differential requirements of feed force and torque , cutting two to three times more easily into plastic than into copper . means are provided to limit the feed force to prevent penetration into the copper foil . means responsive to torque may be employed to retract the cutting tool automatically . a novel spring - loaded telescoping chuck is applicable to limit the feed force in single - spindle or multiple - spindle machines . the sides of the tool are slightly hollow - ground to reduce the feed - force required . the lips may be ground slightly convex to compensate for the elastic indentation of the workpiece .