Abstract: Provided are a hole formation method enabling the formation of a high-quality hole even when a workpiece material is a difficult-to-machining metal material or a fiber-reinforced composite material and a drill bit used in the method. A drill bit includes at least one cutting edge and a face (a leading flank and a trailing flank) positioned in the vicinity of the cutting edge, and on the face, a recess exhibiting a prescribed planar shape (groove) is provided. A hole formation method includes a hole formation step of machining a portion to be processed of a workpiece material by means of drilling to form a hole while a lubricant material for assisting machining process is in contact with the portion to be processed, and in the hole formation step, the drill bit is used.

Abstract: Provided are a hole formation method enabling the formation of a high-quality hole even when a workpiece material is a difficult-to-machining metal material or a fiber-reinforced composite material and a drill bit used in the method. A drill bit includes at least one cutting edge and a face (a leading flank and a trailing flank) positioned in the vicinity of the cutting edge, and on the face, a recess exhibiting a prescribed planar shape (groove) is provided. A hole formation method includes a hole formation step of machining a portion to be processed of a workpiece material by means of drilling to form a hole while a lubricant material for assisting machining process is in contact with the portion to be processed, and in the hole formation step, the drill bit is used.

Abstract: Provided are a hole formation method enabling the formation of a high-quality hole even when a workpiece material is a difficult-to-machining metal material or a fiber-reinforced composite material and a drill bit used in the method. A drill bit includes at least one cutting edge and a face (a leading flank and a trailing flank) positioned in the vicinity of the cutting edge, and on the face, a recess exhibiting a prescribed planar shape (groove) is provided.

Abstract: Provided are a hole formation method enabling the formation of a high-quality hole even when a workpiece material is a difficult-to-machining metal material or a fiber-reinforced composite material and a drill bit used in the method. A drill bit includes at least one cutting edge and a leading flank adjacent to the cutting edge, and the leading flank is set to have a surface roughness Ra of 2.0 ?m or more and 3.0 ?m or less. A hole formation method includes a hole formation step of machining a portion to be processed of a workpiece material by means of drilling to form a hole while a lubricant material for assisting machining process is in contact with a drill bit and/or the portion to be processed, and in the hole formation step, the drill bit is used.