In an embodiment, a drill includes a bar-shaped body rotatable around a central axis. The body includes a first surface located at a first end, a second surface intersecting with the first surface on a front side in a rotation direction, and a cutting edge located at an intersection of the first surface and the second surface. The second surface includes a first region located along the cutting edge, and a second region located on a front side in the rotation direction with respect to the first region. The second surface has a concave shape in a cross section orthogonal to the central axis.

The drill of the present invention includes: a drill main body; a chip discharge flute extending from a tip flank face of the drill main body toward a rear end side of the drill main body and formed on an outer circumference of a tip part of the drill main body; a margin formed at an opposite side of the chip discharge flute in the drill rotation direction; and a body clearance formed at an opposite side of the margin in the drill rotation direction and having an outer diameter smaller than that of the margin. A surface roughness of the body clearance at least along a circumferential direction is equal to or less than a surface roughness of the margin.

A core drill bit can include a first region and a second region. The first region can include abrasive particles in a first bond matrix, and the second region can include abrasive particles in a second bond matrix. The first region is connected to the second region. A composition of the first bond matrix can be different from a composition of the second matrix. In a particular embodiment, the first bond matric can include a Co-containing material.

The invention relates to a rotary cutting tool (1), such as a drill (2) or a reamer (3), extending longitudinally along an axis (4) and comprising at least one main cutting edge (5) so that when the tool (1) is rotated about the axis (4), the tool (1) advances axially to perform a cutting operation on a material.

According to the invention, the tool (1) comprises means for braking (7) the axial advance of the tool (1) during the cutting operation.

A method for producing a cutting tool including a tool body including a hard coating, the method comprising: applying the hard coating to the tool body at least in an area of a cutting edge, a flank, and a chipping surface; depositing the hard coating on a surface of the tool body, of the cutting tool in an area of the cutting edge, of the flank adjacent to the cutting edge, and of the chipping surface adjacent to the cutting edge; sharpening the cutting edge that is provided with the hard coating and that forms a dull rounded edge by partially removing the hard coating in the area of the flank of the cutting edge by laser machining to form a sharpened cutting edge so that an angle is enclosed between a first geometric plane in which a surface of the tool body extends.

A drill includes a flank face, a rake face, and a main cutting edge on a ridgeline between the rake face and the flank face. The main cutting edge has a first curved portion having a curved shape contiguous with the flank face and a second curved portion having a curved shape contiguous with the rake face in a sectional view orthogonal to an extending direction of the main cutting edge. A first curvature radius of the first curved portion is larger than a second curvature radius of the second curved portion.