A drill includes a bar-shaped drill body, a major cutting edge which is located at a front end of the drill body and has a straight-line region in a front view, a rake surface located along the major cutting edge, and a chip discharge flute being extended spirally around a rotation axis of the drill body in a direction from the rake surface toward a rear end of the drill body. The rake surface has a flat region located along the straight-line region.

The invention relates to a tool holding fixture (1) for rotationally driven tools (2), said tool holding fixture comprising a rotationally symmetrical holding body (3) which has a front clamping portion (4) having a holding opening (5) for a tool shaft (6) of the tool (2), and a rear holding portion (7) to be held in a work spindle of a machine tool. To achieve a reduced mass, a lower mass moment of inertia and at the same time high stiffness, a sleeve (11) consisting of a fiber-reinforced plastic is arranged at least in the front clamping portion (4).

An entry sheet of the present invention is used in cutting a fiber reinforced composite material and/or a metal. Moreover, in a cutting method of the present invention, cutting of a fiber reinforced composite material and/or a metal is performed using the entry sheet.

A hand drilling tool of one or more elements coupled therebetween comprising: a chuck (2) tightened in the spindle of a tool machine allowing the tool rotation; an elongated point body (3) with tool diameter (2) having at least four helical grooves developing longitudinally on the point body and defining at least two primary cutters, and at least two secondary cutters; said two primary cutters forming a tip angle; said secondary cutters having a discharge surface S; said discharge surface S is shaped so as to create an interruption between the secondary cutters and the primary cutters by contributing to reduce the operator's effort, to reduce the temperature and to promote the discharge of the worked material. Said point body (3) is formed by a substantially cylindrical first portion and a substantially conical second portion with taper towards the end of the tool.

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.

A tool for machining fiber-reinforced materials, said tool having a tool body having a particular cutting edge that has at least a main function surface and has a diamond coating applied at least to said main function surface. In order to provide a tool and a method which are especially suitable for machining fiber-reinforced materials, the surface of the diamond coating has a reduced peak height Spk of less than 0.25 m.

A drilling tool for producing drill holes includes a tip and a shaft arranged opposite the tip in a direction of a longitudinal axis of the drilling tool. The drilling tool has at least one geometrically defined cutting edge in the tip area, and has an expanded diameter trailing the tip in a longitudinal direction from the tip. The drilling tool has a first area with a first diameter that precedes the expanded diameter, and a second area with a second diameter, larger than the first diameter, that trails the expanded diameter. The drilling tool is distinguished in that the expanded diameter and/or the second area is/are embodied such that chips are produced in the area of the expanded diameter and/or in the second area when a workpiece is machined, chips consistent with those produced when a workpiece is machined with a geometrically undefined cutting edge.

A kind of sawtooth structure with reversed cutting function and its drill series are specifically fitted for drilling carbon fiber reinforced polymers (CFRP). The sawtooth structure is constructed by sawteeth and grooves located on the cutting edges of drill. And the sawtooth structure is helically arranged with a large helix angle around the axis of the drill. It can be divided into left-hand sawtooth structure and right-hand sawtooth structure by the helix angle. The bottom edges of the left-hand sawtooth function as cutting edges, and the rake angles are positive, while the top edges of the right-hand sawtooth are ground as positive rake angles. The sawtooth structure can be applied into multiple drilling tools, which proves to be universal. And it can effectively reduce delamination at both hole entry and hole exit as well as burrs defects. The series of drilling tools are double point angle drill, twist drill and stepped drill with sawtooth structure on the cutting edges. And such forms of drilling tools can achieve hole drilling of CFRP with minimum drilling defects. The drilling performance of the tools is thus improved to a great extent, and the tool life is extended while maintaining low usage costs.

The present invention provides a lubricant material for assisting machining process comprising a high molecular weight compound (A) having a weight average molecular weight of 5?10.sup.4 or higher and 1?10.sup.6 or lower, a medium molecular weight compound (B) having a weight average molecular weight of 1?10.sup.3 or higher and lower than 5?10.sup.4, and a carbon (C) having an average particle size of 100 ?m or larger.

A tunable or tuned boring bar having increased stiffness is provided. Increasing the stiffness of the bar increases the natural frequency, thereby reducing directional deformation of the bar during use. The tunable boring bar includes a distal portion configured to support a tool, a proximal portion configured for attachment to a support structure of a metalworking machine, and a body, which is at least partially tubular, extending between the proximal portion and the distal portion. The tubular portion of the body has an elongated cylindrical cavity. The body of the boring bar includes a core layer formed from a first material and a coating layer formed from a second material. The second material has a higher modulus of elasticity than the first material. In certain configurations, the coating layer is bonded to the core layer by cladding, welding, chemical adhesives, chemical vapor deposition, pulsated plasma diffusion, or combinations thereof.