A drill bit has a tool shank, a center axis, a first cutting region with at least one geometrically defined first cutting edge, the same having a cutting face arranged at a radial distance from the center axis of the drill bit. The first cutting edge forms a countersink angle with the center axis. The drill bit having a chip shaping stage functionally assigned to the first cutting edge formed by the cutting face of the first cutting edge and by a shoulder surface adjoining the cutting face and forming a shoulder angle with the same, wherein the shoulder angle is greater than 90°, and preferably greater than 100°. The cutting face runs at a radial rake angle with respect to an imaginary radial line which cuts the first cutting edge, the same functionally assigned to the cutting face. The radial rake angle is positive.

The drill head (2) extends along a rotational axis (24) in the axial direction (22) and has a central area (6) on the front with first main cutting edges (26), an intermediate area (8) connecting thereto, and an outer area (10) in turn connecting thereto with second main cutting edges (30). The intermediate area (8) in this case expands in the axial direction (22) toward the outer area (10) and in particular forms an expanding conical shell. A centering effect is hereby achieved via the intermediate area (8).

In a drill, a negative hind is provided on a rake face, and a ridge line at an intersecting position of the negative land and a flank face, a ridge line at an intersecting position of the flank face and a margin, and a ridge line at an intersecting position of the negative land and the margin are convex faces in a longitudinal rectangular cross section. When a curvature radius of the convex face of a first ridge line at the intersecting position of the flank face and the negative land is 1, at curvature radius of the convex face of a second ridge line at the intersecting position of the flank face and the margin is 0.8 to 1.5 times the curvature radius of the first ridge line, and a curvature radius of the convex face of a fourth ridge line at the intersecting position of the negative land and the margin is 1.5 to 3.0 times the curvature radius of the first ridge line.

A drill bit includes a shank, a transition portion, and a body portion defining a plurality of axially stacked, progressively sized steps. The steps include a first step and a terminal step coupled to the transition portion. The first step defines two tip flutes each disposed at a tip flute angle. The body portion defines two body flutes each extending from the first step to the transition portion and disposed at a body flute angle different from the tip flute angle. The drill bit includes a bit tip disposed at the distal end of the body portion and having a chisel edge, a first chisel surface on one side of the chisel edge, and a second chisel surface on an opposite side of the chisel edge. The first chisel surface defines a first relief angle. The second chisel surface defines a second relief angle different from the first relief angle.

A spade bit includes a shaft defining an axis about which the spade bit is configured to be rotated. The space bit also includes a blade attached to the shaft and having a first paddle portion and a second paddle portion. In addition, the spade bit includes a tip portion attached to the blade and aligned with the axis. The first paddle portion includes (i) a first leading end portion positioned on a first side of the axis and configured to define a first cutting edge portion, and (ii) a first lateral extension portion configured to define a first sloping surface. The first paddle portion defines a first relief space positioned adjacent to both the first sloping portion and the first leading end portion. The second paddle portion includes (i) a second leading end portion positioned on an opposite second side of the axis and configured to define a second cutting edge portion, and (ii) a second lateral extension portion configured to define a second sloping surface. The second paddle portion defines a second relief space positioned adjacent to both the second sloping portion and the second leading end portion.

The shank (12) of a disposable rotary cutting tool (10) comprises a pipe section (16) cut from a drawn metal pipe. The tool head (14) is formed from a cut-out (18a, 18b) of a drawn metal sheet or a section of a metal tube by non-cutting machining. The pipe section (16) and the tool head (14) are advantageously attached by force fitting.

A drill bit in conjunction with a hammer-drill to penetrate composite metal and non-metal structure or structures including, for example, thick metal or rebar encountered during concrete, rock or masonry boring operations without requiring a change in drill equipment.

A drill bit in conjunction with a hammer-drill to penetrate composite metal and non-metal structure or structures including, for example, thick metal or rebar encountered during concrete, rock or masonry boring operations without requiring a change in drill equipment.

The invention relates to a step drill having a shaft section extending along a longitudinal axis of the step drill and a cutting section with a cutting tip, and having a chip-breaking geometry which comprises a concavely curved surface and is configured such that ribbon chips are broken on the concavely curved surface during rotation of the step drill, whereby the chip-breaking geometry is disposed on a reaming step of the step drill.