Bent Sub 3 : Sub used on top of a downhole motor to give a non-straight bottom assembly. One of the connecting threads is machined at an angle to the axis of the body of the sub. (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}