Pitted Threads : A depression or cavity on a chamfer or thread surface caused by inclusions or porosity exposed after machining or by corrosive attack during storage of the pipe. (Bul 5T1)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}