Abstract: A cutting tool for machining printed circuit boards and the like includes a cutting part having an longitudinal axis of rotation, an outer surface, and a plurality of staggered teeth formed on the outer surface. The cutting part has a first predetermined number of main cutting grooves formed in the outer surface and which extend along the cutting part at a first lead angle, as well as a second predetermined number of divider grooves intersecting the main cutting grooves. The divider grooves extend along the cutting part at a second lead angle. The main cutting grooves and the divider grooves define teeth. The first predetermined number is a prime number and the second predetermined number is greater than the first predetermined number by two, such that the teeth are staggered as viewed in a radial direction which is perpendicular to the longitudinal axis and such that each of the teeth partially overlaps in the radial direction at least another one of the teeth.

Abstract: A multi-lip drill is proposed in which an additional auxiliary swarf flute is arranged in the core region of one or more principal swarf flutes in order to enlarge the swarf space.

Abstract: A drill bit, hvaing heavy-duty cutting elements, is proposed which is intended for rotary, air-cooled application. So that the drill bit can be operated with a relatively low thrust pressure, PCD cutting elements (14) are provided which only slightly overlap the thin-walled cylinder (11, 12) to produce an air gap for cooling and for conveying the drilling dust.

Abstract: A drilling device with an arrangement for the detachable connection of a drill, especially a rock drill, percussion drill, hammer drill, and the like, to a receiving device, e.g. a drive head, which has a longitudinal bore for receiving the shank of the drill, and also has a driving part which is drivingly connectable to a drilling machine and is coaxial with the longitudinal bore. The drilling device furthermore comprises a drive transmitting member movable in the driving part transverse in the longitudinal bore of the receiving device. The drive transmitting or follower member is arranged to engage a bottom face of a recess in the shank of the drill. This recess has a segment-shaped cross section and has a bottom extending continuously over the entire corresponding width of the drill shank.

Abstract: A milling cutter, especially contour milling cutter, which comprises individual cutting elements helically arranged around the axis of the cutter body and connected thereto. These cutting elements are separated from each other in circumferential direction of the cutter body by chip grooves. All of the chip grooves extend helically about the axis of the cutter body in the same sense. Webs project from the cutter body and extend in the same sense helically about the axis of the cutter body while being separated from each other by the above mentioned chip grooves. Along the outer web edges which are located on a common cylinder mantle there are provided depressions or cutouts separated from each other by web sections which form the individual cutting elements.