noncoring bit

noncoring bit

[′nän‚kȯr·iŋ ′bit]
(engineering)
A general type of bit made in many shapes which does not produce a core and with which all the rock cut in a borehole is ejected as sludge; used mostly for blasthole drilling and in the unmineralized zones in a borehole where a core sample is not wanted. Also known as borehole bit; plug bit.