Crane hook surface check is routine work for crane operators everyday, below requirements shall be met:

1.       Pulley shall rotate flexibly on the shaft without obvious looseness;

2.       The pulley rim shall have no damage or crack, or it shall be changed;

3.       Mousing-hook device shall open and close freely, the spring shall be in good condition to avoid steel wire rope sliding from the hook;

4.       The hook shall rotate flexibly on the bearing at cross-girder; round nuts and assembling bolts can not be flexible.

As checking whether there have flaws on hook surface, clean the hook with kerosene firstly, then check the hook with 20 times magnifying glass, make flaw detection with staining method if necessary. For hook of super large sized crane, method of non-destructive inspection for flaws shall also be used to check inside and outside of hook. The hook shall be replaced immediately to avoid accidents caused by hook breakage if flaws are found at inside and outside of hook.