For improving a drill, in particular a spiral drill, comprising a base body extending substantially longitudinally in a direction axial to a drill axis, said base body comprising a drilling portion, wherein a radially inward core region in relation to the drill axis and a radially outer region are provided in the base body in the drilling portion, and the drilling portion comprises a plurality of spiral-shaped recesses in the outer region, and arranged between each two spiral-shaped recesses is a wall part, it is proposed that the drill comprises at least four main cutting edges, in particular exactly four main cutting edge and/or the drill comprises at least three central cutting edge portions.

In this drill, a wall face of a chip removal groove includes a first wall face having a concave curve shape and a second wall face having a straight line shape in a cross section orthogonal to an axis of the drill main body, an extension line of a straight line of the second wall face extends in a direction opposite to a drill rotation direction as the straight line of the second wall face goes to an outer periphery side of the drill main body with respect to a radius line connecting an outer peripheral end of the second wall face and the axis with each other, the cutting edge includes a first cutting edge having a concave curve shape and a second cutting edge having a straight line shape which intersects with the first cutting edge at an obtuse angle.

A rotary tool may include a body having a first part, a second part, a third part, a first cutting edge located at a first end, a flute extending from the first cutting edge toward a second end, and an outer peripheral surface. The outer peripheral surface in the third part may have a first portion. The third part may have a land face, and a second cutting edge located on a ridge line where a first portion and the land face intersect. The land face may have a first region in which a width increases from a side of the first end toward a side of the second end, and a second region that is located closer to the second end than the first region in which a width decreases from a side of the first end toward the second end.

An auger includes a body having a first end, a second end, a stem that defines an axis of rotation, and a flute helically wrapped around the stem. The auger also includes a shank at the first end of the body and a cutting head at the second end of the body. The cutting head includes a cutting edge, a cutting face adjacent the cutting edge, and a back taper surface extending from the cutting edge in a direction opposite the cutting face. The back taper surface defines a back taper angle between an axis perpendicular to the axis of rotation and the back taper surface. The back taper angle is a non-zero angle. The cutting head further includes a feed screw extending from the stem along. The feed screw includes a thread having a pitch and a depth. The pitch is larger than the depth of the thread.

Provided is a method for manufacturing a sintered component, which can suppress occurrence of edge chipping when a through-hole is formed in a powder-compact green body and also has a good productivity. The method for manufacturing a sintered component includes a molding step of press-molding a raw material powder containing a metal powder and thus fabricating a powder-compact green body; a drilling step of forming a hole in the powder-compact green body using a drill; a sintering step of sintering the powder-compact green body after drilling, wherein the drill used for drilling has a circular-arc shaped cutting edge on a point portion thereof.

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.

An auger includes a body with a first end, a second end opposite the first end, a stem that extends from the first end to the second end and defines an axis of rotation, and a flute helically wrapped around the stem. The auger further includes a shank at the first end of the body configured to be received by a power tool and a cutting head at the second end of the body. The cutting head includes a cutting edge, a spur, and a feed screw with a thread. The thread has a pitch and a nonsymmetrical thread profile. The pitch of the thread is at least 2.5 mm.

A drill structure comprises a shank part and a bit part. A web is formed on the front end of the bit part. Two sides of the web are tilted backward to form two cutting faces. At least one chip-discharge groove is formed on the surface of the bit part. Each cutting face includes a primary cutting face and a secondary cutting face. The thickness of the prismatic web edge of at least one primary cutting face is smaller than the outer-side width of the primary cutting face. An auxiliary cutting face is extended to the wall of the flute from the cutting edge of the primary cutting face and a portion of a blade back of the secondary cutting face of another cutting face. The present invention decreases the drilling resistance during drilling a hole and increases the service life of the drill bit.

A drill body and a drill are disclosed. The drill body has a rotational axis and comprises a central chip flute extending along a periphery of the drill body. A central chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The central chip flute cross-section has a depth, as seen along the centre line, and a width as seen perpendicularly to the centre line. The central chip flute cross-section has a maximum depth Dp within a range of Dp=0.75D/2 to Dp=0.90D/2, and a maximum width W within a range of W=0.75D/2 to W=0.90D/2, and wherein the maximum width W extends symmetrically about the centre line.

A drill body and a drill are disclosed. The drill body has a rotational axis and includes a peripheral chip flute extending along a periphery of the drill body. A peripheral chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The peripheral chip flute cross-section has a radially inner side extending perpendicularly to the centre line, and first and second lateral sides connecting to the radially inner side. The radially inner side has a length L1 within a range of L1=0.95D/4 to L1=1.2D/4. Each of the first and second lateral sides has a length LS1, LS2 within a range of D/4 to 1.3D/4. The first and second lateral sides diverge from each other in a direction radially outwards from the radially inner side.