A curved steel fastener located below the travelling block on a drilling rig. It is used to suspend the swivel and drill string in the well. It has an ear-shaped device on either side for the bails that support an elevator.
Hooks can carry loads of 100-650 tons. Small-capacity hooks are used for tubing and sucker rods. Large-capacity hooks used for pipes are attached to a strong interior spring assembly or a hydraulic snubber assembly to lessen damage when making up or breaking out pipe.