A drill bit includes a cutting head and a bit body. The cutting head has a tip and cutting parts. The bit body is connected to the cutting head and has a longitudinal axis extending through the tip. The bit body has chip discharge flutes. The cutting parts are disposed at different angular positions around the longitudinal axis. Each cutting part is concaved inwardly and bounds one of the chip discharge flutes. Each of the cutting parts includes a rake face that has a corner edge adjacent to a respective one of the chip discharge flutes. When a bottom of the cutting head is viewed in a direction parallel to the longitudinal axis of the bit body, the corner edge has an obtuse included angle.

A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.

A hand drilling tool of one or more elements coupled therebetween comprising: a chuck (2) tightened in the spindle of a tool machine allowing the tool rotation; an elongated point body (3) with tool diameter (2) having at least four helical grooves developing longitudinally on the point body and defining at least two primary cutters, and at least two secondary cutters; said two primary cutters forming a tip angle; said secondary cutters having a discharge surface S; said discharge surface S is shaped so as to create an interruption between the secondary cutters and the primary cutters by contributing to reduce the operator's effort, to reduce the temperature and to promote the discharge of the worked material. Said point body (3) is formed by a substantially cylindrical first portion and a substantially conical second portion with taper towards the end of the tool.

Provided is a cutting tool capable of improving both the biting property to a work material and the chip discharge property. The cutting tool includes a drill body rotated about a central axis, four or more cutting edges formed on one end portion of the drill body to face a forward side of a rotation direction, and a flute groove that is formed between the cutting edges adjacent to each other in a circumferential direction and extends substantially spirally along the central axis. (1) The one end portion includes a first tip portion that includes the central axis and has a first tip angle, and a second tip portion that extends from the first tip portion to an outer peripheral edge of the drill body and has a second tip angle larger than the first tip angle, and (2) the drill body includes a first core thickness portion that is formed in such a manner that a core thickness thereof gradually decreases from the one end portion to the other end portion, and a second core thickness portion that is formed in such a manner that a core thickness thereof is constant from the first core thickness portion toward the other end portion.

There is provided a drill including cutting edges wherein each of the cutting edges includes a first cutting edge extending outward in the radial direction from a chisel edge, a second cutting edge having a straight part extending outward in the radial direction from the first cutting edge, a third cutting edge extending outward in the radial direction and extending in a circumferential direction and toward a rear of the drill from the second cutting edge, and a fourth cutting edge extending toward the rear of the drill from the third cutting edge and connected to a leading edge. A first point angle 1 formed by the first cutting edge is set not larger than a second point angle 2 formed by the second cutting edge, and the first point angle 1 formed by the first cutting edge is set within the range of 90 to 140.

A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.

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 for drilling laminates includes at least two main chip flutes separated by corresponding webs. The free end faces of the webs form relief surfaces. At least one secondary flute, which is formed in the periphery of each of the webs divides the web into a main and a secondary web. A main cutting edge is formed by the intersection of a main chip flute and a relief surface on the main web. A secondary cutting edge is formed by the intersection of the secondary flute with a relief surface on the secondary web following the main cutting edge in the direction of operation, the main cutting edges extending to the nominal radius of the drill. The secondary cutting edges terminate at a distance before the nominal radius and axially project from the main cutting edge by an axial overhang at least along their radially outer section.

A bottom cutting step up reamer incorporates a shaft having a first end with attachment features adapted to be received in a chuck. A plurality of bottom cutting edges substantially perpendicular to the shaft are located at a second end distal from the first end. At least one step up land is provided proximate the plurality of bottom cutting edges and spaced toward the first end with a plurality of parallel cutting edges substantially parallel to the shaft.

A hand drilling tool of one or more elements coupled therebetween comprising: a chuck (2) tightened in the spindle of a tool machine allowing the tool rotation; an elongated point body (3) with tool diameter (2) having at least four helical grooves developing longitudinally on the point body and defining at least two primary cutters, and at least two secondary cutters; said two primary cutters forming a tip angle; said secondary cutters having a discharge surface S; said discharge surface S is shaped so as to create an interruption between the secondary cutters and the primary cutters by contributing to reduce the operator's effort, to reduce the temperature and to promote the discharge of the worked material. Said point body (3) is formed by a substantially cylindrical first portion and a substantially conical second portion with taper towards the end of the tool.