CHANGING CUTTING EDGES ON 950 LOADER. NUT STUCK IN 1 1/2 SOCKET. THREADED 1"" BOLT BACK ON NUT. TIGHTENED BOLT HEAD IN VISE. REVERSED AIR GUN 3/4"". BACKED NUT OFF. BOLT CAME LOOSE FROM VISE, STRIKING EE'S CHIN AREA. HAD 6 STITCHES. RETURNED BACK TO WORK ASAP.