Abstract: A die matching system which is preferably implemented in die rolling machinery for fasteners employs witness or reference marks on each of the dies. An eddy current sensor is employed to sense the witness marks and to detect change in the relative position of the witness mark and hence the position of the rotatable dies. The change in position is then processed and a signal is transmitted to servo motors to change the relative position of the dies to compensate for the position changes continuously during the operation of the die rolling machinery. In one preferred form, the witness mark is in the form of a recess milled into the bottom end surface of the cylindrical die.

Abstract: A die matching system which is preferably implemented in die rolling machinery for fasteners employs witness or reference marks on each of the dies. An eddy current sensor is employed to sense the witness marks and to detect change in the relative position of the witness mark and hence the position of the rotatable dies. The change in position is then processed and a signal is transmitted to servo motors to change the relative position of the dies to compensate for the position changes continuously during the operation of the die rolling machinery. In one preferred form, the witness mark is in the form of a recess milled into the bottom end surface of the cylindrical die.