| 摘要 |
Provided is a drill head for deep-hole drilling to which a cutting blade tip (s) is brazed, capable of maintaining a very stable cutting state even if the number of drilling works increases, capable of continuously forming a cutting hole excellent in roundness, cylindricality, and straightness, etc., for a long period of time, and having extremely high accurate processing performance and excellent durability. In a drill head D1 for deep-hole drilling including cutting blade tips 2A to 2C brazed to cutting chip discharge ports 11 and 12 opened on a head distal end surface 1a, guide pads 3A and 3B mounted on a plurality of positions of the circumferential surface 1b at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage 10 communicating with the cutting chip discharge ports 11 and 12, wherein a guide pad portion 4 having an arc surface that slide-contacts with the inner circumference of a cutting hole H is formed on the outer end surface of the circumferential portion cutting blade tip 2B. |
