1, operators can be trained to use the rings. 2. Choose the correct thread type, grade and length of the rings. 3. Whether the working load, thread specification, batch number and manufacturer's mark are clear and legible. 4, each ring must be carefully checked before use, please check whether the ring has been damaged deformation. 5. The lifting ring must be screwed to fit the support surface tightly, no tool is allowed to tighten it, and make sure the thread and thread hole fit tightly.