A metal drilling tool comprising includes a middle axis, a front side and an opposite end, with at least two cutting edges arranged in a region of the front side, a first free surface being associated with each cutting edge. The at least two cutting edges lie on an imaginary first conical surface arranged concentrically in relation to the middle axis, with a first conical angle that opens up towards the opposite end and reaches a maximum of 180°. A centering section includes at least three edges, at least three side surfaces and an imaginary base surface. At least two of the edges lie on an imaginary second conical surface which is arranged concentrically in relation to the middle axis and has a second conical angle that opens up towards the opposite end. The second conical angle is smaller than the first conical angle, such that the imaginary second conical surface, seen from the opposite end, projects opposite the front surface.

A step drill and a manufacturing method for a step drill in which cutting performance of a cutting edge of a step portion can be enhanced are provided. A groove includes a first ground portion forming an area embracing a second cutting edge of the step portion and a second ground portion forming an area on the heel side of the step portion relative to the first ground portion. Therefore, a convex blade part can be formed on a first cutting edge by performing grinding with the first ground portion and the second ground portion intersecting with each other. That is, it is possible to form the second cutting edge into a desired shape during grinding of the first ground portion. Therefore, cutting performance of the second cutting edge can be enhanced.

A three-flute drill includes a body, discharge grooves, cutting edges, thinning edges and gash portions. The discharge grooves are provided in an outer peripheral surface of the body. The cutting edges are provided on ridge sections between inner faces of the discharge grooves and flanks of the body. The thinning edge extends from an end of the cutting edge toward a radially inner side. The gash portion includes an R portion and a straight portion. A first ridge line between the R portion and the flank extends while curving toward a rotation direction, from an end of the thinning edge toward a radially outer side. A second ridge line between the straight portion and the flank extends linearly from an end of the first ridge line toward the radially outer side, and connects to the discharge groove further to the radially inner side than the outer peripheral surface.

The drill is rotatable about a central axis. The drill includes a central axis, a front end and a rear end opposite to each other in a direction along the central axis, an outer peripheral surface, a cutting edge formed at the front end and extending from the outer peripheral surface toward the central axis, a flank face contiguous with the cutting edge, a flute formed on the outer peripheral surface and extending spirally around the central axis from the front end toward the rear end, and a thinning rake face contiguous with the flute. The cutting edge has a main cutting edge extending from the outer peripheral surface and a thinning cutting edge contiguous with an end of the main cutting edge away from the outer peripheral surface. The flute includes a main rake face contiguous with the main cutting edge from the opposite side of the flank face.

A step drill and a manufacturing method for a step drill in which cutting performance of a cutting edge of a step portion can be enhanced are provided. A groove includes a first ground portion forming an area embracing a second cutting edge of the step portion and a second ground portion forming an area on the heel side of the step portion relative to the first ground portion. Therefore, a convex blade part can be formed on a first cutting edge by performing grinding with the first ground portion and the second ground portion intersecting with each other. That is, it is possible to form the second cutting edge into a desired shape during grinding of the first ground portion. Therefore, cutting performance of the second cutting edge can be enhanced.

A rotary cutting tool is provided having a body and a fluid passage. The body has a shank portion and a cutting portion. The body extends lengthwise along a central axis between a shank end and a cutting end. The cutting portion includes a fluted section and a plurality of teeth extending axially outwardly from the fluted section at the cutting end. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to the cutting end. The internal cavity is defined by an interior wall surface. The cutting portion includes a plurality of channels disposed within the interior wall surface and open to the internal cavity. The fluid passage extends through the shank portion to the internal cavity.

A rotary cutting tool having a lengthwise extending central axis is provided. The tool includes a shank portion and a cutting portion. The cutting portion is connected to the shank portion, and includes a fluted section and a plurality of teeth. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to a cutting end. Each tooth includes a front side surface, an exterior side surface, an interior side surface, and an axial end surface. The front side surface intersects with the axial end surface to form an axial end cutting edge that extends radially between an outer radial tip and an inner radial tip, and the outer radial tip is disposed axially outside of the inner radial tip.

A rotary cutting tool cutting insert is provided that includes front, aft, exterior, and interior side surfaces, an axial end surface, and a base surface. The exterior side surface intersects with the front side surface. The interior side surface intersects with the front side surface. The axial end side surface intersects with the front side surface at an axial end cutting edge, with the exterior side surface at a first outer axial edge, and with the interior side surface at a second outer axial edge. The base surface intersects the front, exterior, and interior side surfaces and the aft surface. The base surface intersects the front side surface at an inner edge. An outer radial tip is disposed at a first heightwise distance from an inner edge, and an inner radial tip is disposed at a second heightwise distance from the inner edge.

A cutting tool is described herein that includes a body configured to rotate around a rotational axis. The cutting tool also includes a first plurality of cutting teeth each extending radially outwardly from the body, each cutting tooth of the first plurality of cutting teeth includes a cutting section positioned on a first side of a rotational plane that extends radially outwardly from the rotational axis and a non-cutting section positioned on a second, opposite side of the rotational plane. The cutting tool also includes a second plurality of cutting teeth each extending radially outwardly from the body, each cutting tooth of the second plurality of cutting teeth includes a cutting section positioned on the second side of the rotational plane and a non-cutting section positioned on the first side of the rotational plane.

A cutting insert for a rotary drill tool and a drill tool assembly in which an insert and a support body are coupled via cooperative contact surfaces and a mounting screw. The contact surfaces provide a dual function to axially and rotationally lock the insert at the support body in addition to providing a centring function of the insert.