THE EMPLOYEE STATES HE WAS REMOVING A NUT WITH AN INTEGRATED KEEPER ON IT FROM A BOLT ON A SHOCK WITH AN AIR IMPACT AND BOX END WRENCH. WHENHE ENERGIZED THE IMPACT THE WRENCH MOVED AND THE NU T KEEPER BROKE CAUSING A 1 INCH LACERATION BETWEEN HIS THUMB AND FINGER. THE LACERATION REQUIRED 6 STITCHES.