EE WAS HOLDING A PUNCH WITH CHANNEL LOCKS WHILE COWORKER WAS HITTING THE PUNCH WITH A SLEDGE HAMMER. THEY DO NOT KNOW WHAT HAPPENED, BUT EE HAD BLOOD COMING FROM RIGHT WRIST AREA. X-RAYS REVEALED A SLIVER OF METAL EMBEDDED. ORTH. SPECIALISTS DECIDED NOT TO REMOVE SINCE REMOVAL WOULD CAUSE FURTHER DAMAGE. RESTRICTED DUTY FOR 3 WEEKS.