Hook:A large, hook-shaped device from which the swivel is suspended.
It is designed to carry maximum loads ranging from 100 to 650 tons (90 to 590 tonnes) and turns on bearings in its supporting housing.
A strong spring within the assembly cushions the weight of a stand (90 feet, about 27 meters) of drill pipe, thus permitting the pipe to be made up and broken out with less damage to the tool join threads.
Smaller hooks without the spring are used for handling tubing and sucker rods.
See stand and swivel.