EMPLOYEE STATED THAT HE WAS ASSISTING THE MECHANIC IN REPLACING A HEEL PLATE ON THE LOADER BUCKET; A LARGE WASHER WELDED ONTO THE HEEL PLATE, WHICH WAS BEING USED TO LIFT THE PLATE INTO PLACE, BROKE OFF AS THEY WERE PRYING ON THE PLATE TO HINSTALL IT; THE METAL PLATE FELL OFF, STRIKING HIS RIGHT FOOT BEHIND THE HARD TOE AREA. MISSED WORK ONE SHIFT AND THEN LIGHT DUTY.