A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surface that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.

A deep hole drilling system and methods provide stability and cutting performance to produce deep holes having desired straightness. The system may include a replaceable cutting head provided with a center cutting member and first and second side cutting inserts. The tool provides a major diameter with the OD cutting margins on the replaceable side inserts, as well as possibly cutting margins on the center cutting member. Adjustment mechanisms are provided to adjust the center cutting member and/side cutting inserts.

A drill bit having an interior canal for liquid nitrogen to pass longitudinally through the body of the drill bit. The canal has, on the side of a cutting edge of the drill bit, at least one liquid nitrogen ejection duct that opens near the cutting edge which is formed by an insert made with polycrystalline diamond fixed to the body of the drill bit. A device for drilling a metal-composite stack includes the drill bit, a liquid nitrogen production unit and a distribution network to distribute the liquid nitrogen. The device drills through a metal-composite stack in a single pass of the drill bit. The liquid nitrogen at cryogenic temperature is conveyed close to the cutting edge, at least while the cutting edge is in contact with the metallic material.

The invention is directed to a drill system that better uses the power curve of modern machine tools. The drill system uses IC inserts to perform the major hole diameter cutting, and a central drilling system that cuts the remaining minor diameter portion of the hole, and is configured to see less cutting surface footage, due to its position from the rotating center of the tool. A connection between the drill head and a holder body secures the drill head in a manner to effectively absorb lateral drilling forces. The drill system allows for a large diameter deep hole that remains straight throughout to be drilled at higher speed and lighter feed rates thus offering a more productive tool that takes advantage of the power curves and lower thrust capabilities of modern machine tools.

A drilling tool for machining structural components made of a titanium alloy includes: a support, which extends along an axis of rotation in the axial direction, the support having an end face with a receptacle disposed centrally therein; a plurality of cutting inserts inserted at the end face in a manner that forms a flat drill, each cutting insert having an active insert cutting edge extending transversely to the axial direction; and a drilling tip disposed in the receptacle and having at least two tip cutting edges, the tip cutting edges extending outward from the axis of rotation and being adjoined in each case by at least one active insert cutting edge.