A spirally-fed drilling and milling cutter to be driven spirally in order to drill and mill includes a shank, a groove at one of a plurality of offset positions at one end of the shank, a blade at a bottom side of the groove, and a spiral flute on the periphery of the main body of the shank, wherein the spiral flute has a flute end connected with the groove. When the cutter is rotated at high speed and in high torsion, drilling/milling chips are pushed upward, along with a cutting liquid, through the spiral flute out of a hole being made. Thus, the heat generated by the cutting action is reduced, and the chips are efficiently discharged, allowing the cutting edges to stay sharp and the cutter to make deep holes.

A drill bit includes a body having a first end, a second end, an axis of rotation defined through the first and second end, and a body flute that extends along the axis of rotation at a helix angle. The drilling tool also includes a cutting head attached to the second end of the body. The cutting head includes a first land, a second land, and a cutting head flute. The cutting head flute is defined between the first land and the second land. The cutting head flute extends along the axis of rotation at the helix angle such that the body flute and the cutting head flute form a continuous flute.

The present invention relates to a step drill bit, characterized in that the step drill bit has a hole processing portion and at least two flutes extending on the hole processing portion, the hole processing portion comprising step sections, each step section and the at least two flutes forming at least two cutting edges distributed in a circumferential direction of the step section, wherein, the at least two cutting edges on at least one of the step sections at least comprise a first cutting edge and a second cutting edge, wherein the first cutting edge and the second cutting edge are respectively constructed in at least two-segment style, and therefore respectively include at least two cutting edge segments, wherein the first cutting edge and the second cutting edge are at least partially different from each other in the structure of their cutting edge segments, or one cutting edge of the first cutting edge and the second cutting edge is formed in one-segment style, while the other cutting edge is formed in at least two-segment style, and thus includes at least two cutting edge segments. The present invention further relates to a method for drilling a workpiece by using a step drill bit.

A cutting tool (2)in particular a rotary toolis described, having a cutting edge (4) from which a rake face (6) and a clearance face (8) extend, characterized in that a groove (12) is introduced into the clearance face (8) in a region along the cutting edge (4) so that a part of the clearance face (8) is formed as a wear face (14) that extends between the groove (12) and the cutting edge (4) and is bounded by the groove (12) and the cutting edge (4). The groove (12) advantageously limits the wear of the cutting tool (2) in the region of the cutting edge (4) on the wear surface (14), so that overall the frictional forces that occur are kept small and the service life of the cutting tool (2) is extended. Furthermore, a cutting element for a cutting tool (2) as well as a method for manufacturing the cutting tool (2) are described.

The present invention relates to a drilling tool and method for modifying a blind hole in a blade root insert of a wind turbine. The invention further relates to an apparatus and method for cleaning a blind hole. The method for modifying a blind hole comprises: removing a blade screw located in the blind hole, inserting a drilling tool into the blind hole, fixing the drilling tool in a drill, recessing the blind hole by a predetermined depth, with a maximum diameter of the end section and of the hole bottom after recessing being smaller than or equal to a diameter of the end section prior to recessing and a transition from the end section to the hole bottom being round after recessing, removing the drilling tool and the drill, mounting the blade screw in the modified blind hole.

A drill bit for drilling laminates includes at least two main chip flutes separated by corresponding webs. The free end faces of the webs form relief surfaces. At least one secondary flute, which is formed in the periphery of each of the webs divides the web into a main and a secondary web. A main cutting edge is formed by the intersection of a main chip flute and a relief surface on the main web. A secondary cutting edge is formed by the intersection of the secondary flute with a relief surface on the secondary web following the main cutting edge in the direction of operation, the main cutting edges extending to the nominal radius of the drill. The secondary cutting edges terminate at a distance before the nominal radius and axially project from the main cutting edge by an axial overhang at least along their radially outer section.

A saw blade can include a blade body having a cutting edge defined by multiple teeth. The teeth can be disposed in a repeating pattern including a raker tooth, a first set tooth having a light offset to a right side of the blade body, a second set tooth having a heavy offset to the left side of the blade body, a second raker tooth, a third set tooth having a light offset to the left side, and a fourth set tooth having a heavy offset to the right side of the blade body. Each tooth can include a tip, rake face, gullet having a gullet depth, and one or more clearance surfaces. The pitch distance and gullet depth of the heavy offset teeth can be less than the pitch distances and gullet depths of the remaining teeth to provide an increased amount of strength for the heavy offset teeth.

A drill of the present invention includes: a drill main body; a plurality of convex-arc cutting edges which are formed on a tip side of the drill main body from an outer periphery of the drill main body to a chisel edge provided near to a rotational axis; second faces which are each formed in an approximately band shape and are each formed along each of the convex-arc cutting edges on a back side of the convex-arc cutting edge in the rotational direction; third faces which are each formed to be continuous with a back side of each of the second faces in the rotational direction; and fourth faces which are each formed to be continuous with a back side of each of the third faces in the rotational direction.

A drill has a central axis, a front side, a circumferential surface, at least two main edges on the front side, which reach up to the circumferential surface and merge there with secondary edges, at least two central edges extending from the end of the main edge facing away from the circumferential surface, cutting surfaces associated with the main edges and central edges, chip flutes associated with the main edges and central edges and introduced into the circumferential surface, at least one cross edge adjoined by the ends of the central edges facing away from the main edges which passes through the central axis, a point thinning and chip run-up shoulders associated with at least the cutting surfaces of the central edges. An angle of the chip run-up shoulder decreases in the region of the point thinning towards the central axis as the distance from the front side increases.

A drill bit cutter and a drill bit are disclosed. The drill bit cutter defines a rotation axis and includes two cutter parts located at two sides of the rotation axis in a transverse direction, each cutter part having a front cutter face, a rear cutter face, and a blade formed between the front cutter face and the rear cutter face. The front cutter face of each cutter part is ground to form a ground shaped face. The ground shaped faces of the two front cutter faces are different, At least a local height difference is thereby produced in the two blades. Drilling precision can be increased while extending cutter life.