Reverse Circulation (RC) drilling utilizes a drill bit that features protruding tungsten-carbide buttons to cut through rock, clay and earth. The drill rods themselves are of a dual wall design.

A downhole hammer delivers rapid impacts via a reciprocating piston, transferring this energy through the drill bit. This concussive force hammers the bit into the rock, pulverising it, whilst rotating the drill rods ensure that the drill bit hits new sections of rock with each impact. Inside the drill bit, an inner tube is used to achieve circulation, with compressed air being injected between the tubes to flush the sample from the hole and up through the inner tube to the surface.