A hole-saw, including a sidewall and an endcap, is provided. The endcap includes projections that fit within notches of the sidewall to form a brazed or welded joint that couples the endcap to the cylindrical sidewall. The projections extend through the notches and are brazed or welded to the base of the sidewall. The endcap couples to the sidewall to form a cylindrical hole saw body. The endcap rotates and supports the hole-saw during operation.

A tool for machining a workpiece. The tool comprises a cutting insert with a shank, which extends along a cutting insert longitudinal axis, and with at least one cutting edge, wherein at least a part of the cutting insert is made of a first material. The tool further comprises a tool holder which extends along a holder longitudinal axis and comprises on an end-face end a cutting insert receptacle for receiving the cutting insert shank, wherein the cutting insert receptacle is designed as a cup-shaped recess in the tool holder. The tool further comprises an attachment element which is fixedly connected to the cutting insert and extends in a circumferential direction around the cutting insert shank, wherein at least a part of the attachment element is made of a second material which differs from the first material. Still further, the tool comprises a fastening element for fastening the cutting insert on the tool holder, wherein, in a mounted state of the tool, the fastening element contacts the attachment element in order to fasten the cutting insert on the tool holder.

A shank comprises a captive portion, comprising a longitudinal central axis, a captive end, a first set of first structures, and a second set of second structure. The second set of the second structures is closer to the captive end than the first set of the first structures. The first set of the first structures has a first axial compliance coefficient along the longitudinal central axis. The second set of the second structures has a second axial compliance coefficient along the longitudinal central axis. The first axial compliance coefficient of the first set of the first structures is greater than the second axial compliance coefficient of the second set of the second structures.

The present invention relates to a multi-material rotary cutting tool (1) and a method for manufacturing such a tool that includes at least one continuous or substantially continuous cutting edge (8, 9) made of at least two different successive materials. The extremity or top (10) of the tool is a point off-centered in relation to the axis of rotation (5) of the tool.

A hole-saw, including a sidewall and an endcap, is provided. The endcap includes projections that fit within notches of the sidewall to form a brazed or welded joint that couples the endcap to the cylindrical sidewall. The projections extend through the notches and are brazed or welded to the base of the sidewall. The endcap couples to the sidewall to form a cylindrical hole saw body. The endcap rotates and supports the hole-saw during operation.

A drill bit for drilling a hard material includes a drill bit blade defining an axis of rotation and including a first side and a second side positioned respectively on first and second lateral sides of the axis of rotation. The drill bit blade further includes a blade tip point that is laterally biased relative to the axis of rotation, and a first blade edge and a second blade edge starting at the blade tip point and ending at the first side and second side, respectively. An angular bisector between the first and second blade edges is inclined at an angle relative to the axis of rotation.

A method of forming a shank comprises arranging first structures in a first set of the first structures and second structures in a second set of the second structures such that the first structures and the second structures extend away from a longitudinal central axis in a direction normal to the longitudinal central axis and such that ends of the first structures and the second structures, farthest away from the longitudinal central axis, form cylindrical surfaces, parallel to the longitudinal central axis and equidistant from the longitudinal central axis. The method further comprises indirectly bonding the first set of the first structures to the second set of the second structures, thereby forming the shank. At least one of the first structures consists of a first material. At least one of the second structures consists of a second material, such that the first material is different from the second material.

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.

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.

A drill structure includes a shank part and a flute part. A chisel edge is formed on the front end of the flute part and two primary relief faces with tile directions toward the shank part are symmetrically formed on the two sides of the chisel edge. Each primary relief face has a cutting edge, a knife-back edge, and an outer edge. The outer edges are respectively helically extended around the periphery of the flute part to form two helical cutting edges and two helical grooves. Two assist relief faces are respectively formed on the inner walls of the two helical grooves, and every assist relief face is connected with the cutting edge of one primary relief face and portion of the knife-back edge of another primary relief face. The drill structure can decrease the thickness of the chisel edge, reduces the resistance during drilling, and increases the life.