1, there is a significant permanent deformation or shaft pin can not rotate freely. 2. The wear of any section of buckle and shaft pin is more than 10% of the original size. 3. Crack in any part of the shackle. 4. Shackles should not be locked. 5, unfastening test is not qualified. The phenomenon of crack in the shackle conforms to Article 3 of the scrap standard, so it should be scrapped.