External Upset 3 : An extra-thick wall at the threaded end of drill pipe or tubing. Externally upset pipe does not have a uniform outside diameter throughout its length but is enlarged at each end. (WLOP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}