Abstract: There is provided a drill bit comprising a bit body having a receptor portion formed therein, the receptor portion being filled with a cutting oil; a drilling portion extended from one end of the bit body, having a channel coupled to the receptor portion formed therein, and having an opening formed in one end thereof and connected to the channel; and a cutting portion provided at a periphery of the opening of the drilling portion for drilling a workpiece, wherein the channel of the drilling portion has a small diameter in order that the cutting oil is not discharged outside of the channel by external pressure or gravitational force, and the channel of the drilling portion has a structure in which capillary action occurs due to cut chips flowing through the channel during drilling of the workpiece so that the cutting oil may be discharged by the capillary action.

Abstract: There is provided a drill bit capable of performing a continuous drilling operation on a high-strength workpiece such as a tempered tile and the like. The drill bit comprises a bit body having a receptor portion formed therein, the receptor portion being filled with a cutting oil; a drilling portion extended from one end of the bit body and coupled to the receptor portion of the bit body to form a channel in which a capillary phenomenon occurs, and having an opening formed in one end thereof; and a cutting portion provided in the opening of the drilling portion to drill a workpiece. The drill bit thus configured may be useful to enable a continuous drilling operation on the high-strength workpiece, to enable the refilling of a cutting oil used to cool the high-strength workpiece, to shorten a time for the drilling operation on the high-strength workpiece, and to drill the high-strength work-piece to the maximum extent using the minimum number of drill bits.