Magnetic Poles : The area on a magnetized pipe from which the magnetic field is "leaving or returning," usually at its end when longitudinally magnetized. (RP 5A5)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}