WT type drill collar Rotary Slips can accommodate drill collars from 4 1/2 in (114.3mm) to 9-1/2in(241.3mm) OD.
They are designed and manufactured accordign to API Spec 7K Specification for drilling and well servicing equipment.
Each piece of drill pipe slip or drill collar slip is provided with an axial dovetail groove and is provided with a liner plate and a slip press plate. When the slip sits on the turntable bushing, it holds the drill string under the action of its own weight. When the drill string moves downward, the slip moves downward. Because the shape of the slip body is a conical body with a large upper part and a small lower part, the rotary bushing is matched with the slip cone to make the slip body radial close to the axis and clamp the drill tool. When lifting the drill string, the slip tooth structure and the back cone structure are used to make the slip and the drill string unstuck under the weight of the slip, and the slip can be lifted.