... diamond surface-set core bit, PDC bits (core or noncoring), casing shoes, reaming shells, overshot, hoisting plug, water swiel, wrench. ... quality standards as British / Swedish / DCDMA / CDDA / Metric standards, and used around the world in a great variety of applications. We ... outstanding quality and satisfied service.1.Drill rod: BQ, NQ, HQ , PQ , NT, HT, BTW, NTW casing tube: BW, NW, HW, HWT2 ...