Knife (Or Razor) Edge : A sharp edge at the end of the pipe producing no face; caused buy an excessively small chamfer diameter and/or excessive ID bevel. (Bul 5T1)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}