EE WAS REMOVING A DUST PLUG FROM A COM-LOCK TYPE GREASE COUPLING TO FILL THE BULK GREASER ON A CAT 992 G LOADER. THE SPIRAL WOUND WIRE RING THROUGH THE DUST PLUG HAD BEEN DAMAGED. WHEN THE EE PUT HIS FINGER THROUGH THE RING AND PULLED TO OPEN A PROTRUDING WIRE PUNCHURED HIS FINGER THROUGH HIS LEATHER WORK GLOVE.