1. The hook used in the lifting mechanism driven by manpower is tested with 1.5 times the rated load as the inspection load.
2. The hook used for the power-driven lifting mechanism shall be tested with 2 times the rated load as the inspection load.
3. After the hook is removed from the inspection load, there should be no obvious defects or deformation, and the increase in opening degree should not exceed 0.25% of the original size.
4. For hooks that have passed the inspection, a mark should be printed in the low-stress area of the hook, including the rated lifting weight, factory mark or factory name, inspection mark, production number, etc.
The hook should be scrapped when one of the following situations occurs:
① Crack;
②Dangerous section wear reaches 10% of the original size;
③The opening degree is increased by 15% compared with the original size;
④The torsion deformation of the hook body exceeds 10°;
⑤The dangerous section of the hook or the neck of the hook is plastically deformed;
⑥The hook thread is corroded;
⑦When the wear of the hook bushing reaches 50% of the original size, the bushing should be replaced;
⑧ When the mandrel of the piece hook is worn to 5% of the original size, the mandrel should be replaced.