The hook block assembly is the hoisting equipment for oil drilling rig and also the assembly of travelling block and hook, which can shorten the length between travelling block and the hook. During petroleum drilling operation, it is mainly used to hoist and trip the drill pipe, replace bits, run the casing, etc. and it also can be used to eliminate accidents during slight pipe-sticking and touching resistance. It can be used together with the crown block, swivel, hoisting ring and others with the same grade, which conforms to API specification.
