Drill Bit
A drill bit is a rock-cutting tool used for drilling a hole in the ground. A drill bit could either have fixed cutting blades or rollers. They use different types of cutters made of steel, tungsten carbide, polycrystalline diamond compact (PDC) material, or diamonds for cutting rocks. The design and type of cutting teeth are selected based on the type of rocks to be drilled. Drill bits are broadly classified as roller cone or fixed cutter bits. They are further classified based on the material used for cutting teeth, bearing type, suitability for cutting different compressive strength rocks etc.
A drill bit is connected to the drill string and is run in the well. The drill string is rotated at the surface, which turns the bit at the bottom of the hole to cut the rock into small pieces called drilled cuttings. Downhole drive mechanisms like Positive Displacement Motors (PDM) or Turbines are also used for generating bit rotation and torque downhole.