DRILL BIT

摘要

PURPOSE: A drill bit is provided to suppress friction heat during an initial cutting process and smoothly supply cutting fluid. CONSTITUTION: A drill bit(100) comprises a body(110), a drilling unit(120), and a cutting unit(130). A receiving portion(112) of the body is filled with cutting fluid(150). The drilling unit comprises a supply passage of a capillary tube structure(121), an opening(122), and a protrusion(123). The supply passage is connected to the receiving portion of the body. The opening is formed at one end to the supply passage. The protrusion is formed in an opening area. The protrusion has a small diameter to facilitate initial cutting work. The cutting unit comprises an initial cutting unit(131) and a main cutting unit(132). The initial cutting unit is formed on the external side of the protrusion of the drilling unit. The main cutting unit is expanded from the initial cutting unit and is formed on the outer surface of the end section of the drilling unit.