Assertion: drill bit | /r/CapableOf | ream borehole
Facets:
Source sentences:
text: Drill bits are classified in three groups according to purpose or use: for continuous drilling (crushing of rock over the entire face of the borehole), for core drilling (crushing of rock in a ring around the wall of a borehole, retaining the central part of the core), and for special purposes (drilling out cement in a pipe string, reaming a borehole, and so on).