The first drill bit is a hammer drill bit, suitable for drilling concrete. The second is a twist drill bit, which can drill metal and wood. The third is a reaming drill bit, used for enlarging holes.
Drill bits are tools used to drill through or blind holes in solid materials, and can also be used to enlarge existing holes. Commonly used drill bits mainly include twist drills, flat drills, center drills, deep hole drills, and core drills. Although reaming drills and countersink drills cannot drill holes in solid materials, they are conventionally classified as drill bits.
During the digging process, the drill bit rotates with the vertical shaft and simultaneously moves axially. The soil is cut under the action of the torque and axial force of the drill bit, and is loosened by the squeezing and centrifugal force of the working blades, forming a soil flow that presses against the pit wall and is simultaneously lifted to the surface along the blade. When the soil flow reaches a point where there is no pit wall obstruction, the broken soil is thrown around the pit due to centrifugal force, completing the digging process.
