EE WAS WORKING ON SCALER IN UG SHOP. EE WAS USING METAL BAR TO POSITION HOOD MOUNT RAILING INTO POSITION TO BE WELDED. THE BAR SLIPPED CAUSING THE EE TO BE THROWN OFF BALANCE AND FOR HIS RIGHT HAND TO SLIDE DOWN METAL FRAME FAR ENOUGH TO CUT RIGHT RING FINGER ON TOP OF LAST JOINT(BELOW FINGER NAIL). LACERATION REQUIRED THREE STITCHES. EE WAS RELEASED TO WORK NEXT SCHEDULED SHIFT.