EE WAS USING A JACK HAMMER TO REMOVE THE RAW MILL FEED END MANDOOR WHEN A 3/16"" PIECE OF THE HAMMER BIT BROKE LOOSE AND TRAVELED APPROX. 6 FEET STRIKING HIM IN THE LOWER LIP PASSING THROUGH AN D IMBEEDING IN HIS GUM. INJURY REQUIRED MEDICAL ATTENTION WHICH CONSIST OF REMOVING THE 3/16"" PIECE OF METAL FROM THE GUM AND EIGHT STITCHES INSIDE THE LIP.