Method and apparatus for making dies and rolls

Claim 1

A METHOD OF FORMING A METAL FORMING ROLL WHICH COMPRISES FORMING A CYLINDRICAL ROLL BLANK, MACHINING AN OUTSIDE SURFACE OF THE ROLLS AND FACING THE ENDS OF THE ROLL PROVIDING END FACES, BORING A BORE THROUGH THE ROLL, MILLING A KEYWAY IN THE BORE, HEAT TREATING THE ROLL, GRINDING THE INSIDE AND OUTSIDE SURFACES AND THE END FACES OF THE ROLL, AND TURNING THE ROLL WHILE UPWARDLY MOVING A TAPERED ELECTRODE TANGENTIALLY OF THE ROLL AND ELECTRIC SPARK BURNING A TAPERED GROOVE IN THE ROLL WHILE THE CUTTING ZONE IS IMMERSED IN OIL TO PERMIT THUS MACHINED PARTICLES TO FALL AWAY FROM THE CUTTING ZONE TO MINIMIZE SHORT CIRCUITS.