Featheredge : A thin sharp crested portion of a thread normally formed when the starting thread on round or buttress (pipe threads) runs out to the face of the pipe and not on the chamfer. (Bul 5R1)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}