Drift Mandrel : A precision dimensioned cylinder sized to pass through each diameter and weight of pipe. It is passed through the pipe ID to locate obstructions and/or to assure compliance with appropriate specifications. (RP 5A5)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}