Core drilling
Drilling and coring in rock

Rotational coring involves cutting a cylindrical sample of rock and bringing it to the surface for visual identification, geotechnical laboratory testing or mineral exploration evaluation.

Early coring methods obtained complete samples by rotating a thick tube with a slit in the part in contact with the rock. This slot facilitated the passage of water to cool the tool and evacuate cutting debris. Wear on the rock was achieved by introducing steel...