Drill Bit

Trépan
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Drilling tool that crushes or cuts rock to increase the depth of the borehole. Drill bits consist of three rotating cones (roller cones) with teeth made of very hard steel, tungsten carbide, or even synthetic or industrial diamonds for cutting through very hard rock. Drill bits grind, cut, scrape, crush or pound the rock. Drilling fluid is expelled through jets in the drill bit to clean it and carry cuttings to the surface via the annulus between the wellbore and the drill string.