Slips are used to grip the drill string or casing during connection and tripping. They contain dies and inserts allowing them to grip the outside diameter of the pipe. They fit around the pipes while lowering them and go into the opening within the rotary table.
Slips, that handle larger diameters of pipes “Casings”, do not go into the rotary table, but are put on the top of the rig floor. This type of slips are called spiders.
Some slips are ordinary or without any powering system. Others are operated by powering systems “using spring coil or compressed air”. Automatic slips are a new technology of slips which are operated without the Roughnecks.
There are many types of slips such as drill pipe rotary slips, drill collar slips, drill pipe powered slips (powered by coil spring or air), air controlled casing spider (for heavy duty purposes), and automatic slips.