62 and a top coining punch 74 that replaces the pilot hole punch 68 the top coining punch 74 includes a guide hole 76 therein extending into the top coining punch 74 along the axis 40 of the rotor retaining screw hole 30 the guide hole 76 is adapted for receipt of a locator pin 78 extending from the base coining punch 72 the locator pin 78 extends from the base coining punch 72 along an axis of the base coining punch 72 coincident with the axis 40 of the rotor retaining screw hole 30 and is adapted for receipt within the guide hole 76 in the top coining die 78 the first and second surfaces 44 46 and the through hole 50 of the conical web 42 are formed in one operation by engaging the locator pin 78 of the base coining punch 72 in the guide hole 76 of the top coining punch 74 and pressing the base and top coining punches 72 74 into the annular flange 26 to thereby cause material in the annular flange 26 to be deformed around the top and bottom coining punches 72 74 and an exposed portion of the locator pin 78 in the exemplary embodiment the top coining punch 74 has an outer diameter significantly larger than the through hole 50 centered about the axis 24 of the retaining screw hole 30 and a distal end having a reverse conical configuration the top coining punch 74 is pressed into the annular flange 26 to a depth below the second surface 36 of the flange to form.