Definition
Slips — Slips are wedge-shaped, hinged tools with hardened, gripping dies that are set into the tapered bowl of the rotary table or a spider to suspend a string of drill pipe or casing when it is not hanging from the elevator.
Also known as: rotary slips, drill pipe slips, casing slips
What slips do
Slips hold the drill string or casing in the rotary table while the elevator is released to add or remove a joint. Each slip segment carries hardened, toothed inserts (dies) on its inner face and a matching taper on its back that mates with the bowl. As the string’s weight pushes down, the taper drives the slips inward, and the dies bite into the pipe body, converting axial load into gripping force.
Slips are sized to the tubular outside diameter and come as manual (hand) slips or as inserts for power slips and spiders. On heavier strings, rotary slips are replaced by a power slip or a spider to reduce manual handling and improve grip distribution.
Slip crushing and correct use
Because the slips squeeze the pipe body, excessive load or worn dies can cause slip crushing — localized deformation or collapse of the tube. API RP 7G-2 provides guidance on the relationship between hook load, slip length and the crushing limit. Correct die condition, matched taper and even seating are essential to avoid crushing and slip marks that can initiate fatigue cracks.
Why it matters for rentals
Worn or mismatched slips damage rental tubulars and create a dropped-string hazard. Rental slips should have sharp, undamaged dies matched to the exact pipe size and a bowl taper in good condition. Browse our handling tools or contact us with your pipe size and hook load for the right set.