Definition - What does Gauge Cutter mean?
Gauge cutters are used to confirm that a bore is a correct diameter throughout its whole length. The gauge cutters are inserted into the bore and pulled through the bore’s length before the pipes or conduits are inserted into the bore. This allows the drilling crew to confirm the bore is large enough (throughout its entire length) to accept the pipes or conduits intended for the bore without the pipe's binding or becoming trapped in the bore.
Trenchlesspedia explains Gauge Cutter
Anyone who has ever had to redrill a screw hole because the drill bit you used was 1/64 inch too small can appreciate a gauge cutter's attributes. A bore may be too small because of incorrectly sized drill bit or the collapse of the bore.
Because the gauge cutter is slightly larger or equal to the size of the bore, it's also useful part of the wireline operator's kit. The floor crew breaks the drill string at the drill-floor level. The wireline operator fits the gauge cutter – which resembles a piece of pipe with slots cut in the sides – over the end of the drill string that's still in the hole and lowers it to the bit. The wireline operator can then raise the gauge cutter, which will clear a path for the removal of the bit from the bore.