A drill head includes a first attachment surface attached to a holder, a head tip surface opposite to the first attachment surface in an axial direction along the central axis, and a head outer peripheral surface continuous with the first attachment surface and the head tip surface. The head outer peripheral surface is provided with a first flute and a second flute extending helically about the central axis from the head tip surface to reach the first attachment surface. The first flute and the second flute are symmetric with respect to the central axis. Each of the first flute and the second flute has a first end and a second end that face each other with a space between them in a circumferential direction along a circumference centered on the central axis.

There is provided a drill insert for drilling metallic or other materials, comprising a drill insert body with first and second lands at the outside diameter of the body that interface with the wall of a drilled hole. There is provided a coolant relief arrangement at the outside diameter of the drill insert by a plurality of coolant supply channels extending between the leading edge and trailing edge of the interface, to provide coolant relief to the outside diameter of the drill insert at the interface with the drilled hole. The drill inserts of the invention provide reduced friction and heat generation while maintaining high stability, and operate to prevent accumulation of materials on surfaces of the drill inserts at the outside diameter of the drill insert. This enables higher penetration rates and operating speeds while maintaining integrity of the drill inserts.

There is provided a drill tool assembly for drilling metallic or other materials, comprising a holder having a mounting slot in which a cutting insert is positioned, and a through tool coolant supply system. The drilling tool system allows for the application of coolant to the rake surfaces of the cutting insert in a manner which facilitates enabling higher penetration rates while maintaining integrity of the cutting edges of the cutting insert. The drilling tool system comprises a holder having a rotational axis and mounting slot. A cutting insert with sides positioned adjacent the side surfaces of the mounting slot and cutting edges extending from the rotational axis is mounted in the slot. The insert includes rake surfaces adjacent the cutting edges that are positioned above the mounting slot. At least one coolant channel is disposed with at least one coolant outlet directed at the sides of the insert at a position below the rake surfaces. The coolant outlet is configured to disperse coolant in a curtain across the entire rake face of each cutting edge.

A cutting insert rotatable about an axis, has opposing front and rear surfaces interconnected by an insert peripheral surface, the insert peripheral surface having first and second side surfaces spaced apart by first and second land surfaces. First and second land edges extend along the first and second land surfaces, respectively. A first front edge formed at the intersection of the front surface and the first side surface includes a cutting-edge portion, and a second front edge formed at the intersection of the front surface and the second side surface is devoid of a cutting-edge portion. A cutting profile formed by rotating the cutting-edge portion about the axis is located axially forward of the second front edge. The cutting insert is releasably secured to a tool shank, the cutting insert being located between two protuberances protruding from a forward end portion of the tool shank.

A step drill bit includes a body with a plurality of cylindrical steps of increasing diameter from a front end toward a rear end, a flute extending from the front end toward the rear end, and cutting edges at junctions between each step and the flute. A cutting insert with a hardness greater than the hardness of the body is coupled to the front end portion and at least partially defines a cutting head portion. The cutting head portion includes a center cutting tip, a cutting edge extending radially outward from the cutting tip, a rake face extending from the cutting edge toward the rear end portion, a relief face extending from the cutting edge in a circumferential direction opposite a rotational cutting direction of the drill bit, and a chip clearing recess in communication with the flute, with the rake face facing the chip clearing recess.

There is provided a drill tool assembly for drilling metallic or other materials, comprising a holder having a mounting slot in which a cutting insert is positioned, and a through tool coolant supply system. The drilling tool system allows for the application of coolant to the rake surfaces of the cutting insert in a manner which facilitates enabling higher penetration rates while maintaining integrity of the cutting edges of the cutting insert. The drilling tool system comprises a holder having a rotational axis and mounting slot. A cutting insert with sides positioned adjacent the side surfaces of the mounting slot and cutting edges extending from the rotational axis is mounted in the slot. The insert includes rake surfaces adjacent the cutting edges that are positioned above the mounting slot. At least one coolant channel is disposed with at least one coolant outlet directed at the sides of the insert at a position below the rake surfaces. The coolant outlet is configured to disperse coolant in a curtain across the entire rake face of each cutting edge.

A cutting head rotatable about a central axis, includes a tip portion and an intermediate portion. The tip portion has an axially forwardmost tip point contained in the central axis and at least two axially forward-facing front surfaces, each front surface having a radially extending cutting edge. The intermediate portion has at least two head lands circumferentially alternating with at least two chip evacuation passages, each head land having a leading edge extending axially rearwardly from the tip portion. The cutting edges are contained in an imaginary annular ring surface, and a first imaginary radial plane containing the central axis intersects the imaginary annular ring surface to form two imaginary radial cutting profiles. Each imaginary radial cutting profile has consecutively radially outward extending first, second, and third cutting profile portions, and the second cutting profile portion includes first and second concave sub-portions spaced apart by a first convex sub-portion.

A drilling tool is provided, which is configured to prevent an insufficient chip discharge ability thereof. The drilling tool includes a cutting insert having a cutting edge at a leading end portion, and a body to which the cutting insert is mounted. The drilling tool also includes a recessed part provided on an outer peripheral surface of the body and extending to a leading end of the body, and an oil supply port provided on a base end side of the recessed part and supplying cutting oil, passing through the inside of the body, to an outer peripheral side of the body. In a case where the drilling tool further includes a guide pad that comes into abutment with an inner wall surface of a hole cut by the cutting insert, and a fastening screw for fixing the guide pad to the body, the oil supply port may be provided at a position further toward the base end side of the body than a position of the fastening screw.

An insert holder includes a cutting portion and a shank portion. The insert holder further includes a cavity which includes a cavity chamber and a plurality of cavity through recesses which serve to reduce the weight of the insert holder. The plurality of cavity through recesses open out to the cavity chamber and to the periphery of the shank portion. A cutting tool is provided having a cutting insert releasably attached to the insert holder.

The combination tool (2), in particular a drilling/chamfering tool, comprises a drill (6) extending in the longitudinal direction (4) with a clamping sleeve (8), which is designed to receive the drill (6) and fasten the drill (6) at a variable length and which has a holding seat (38) for a cutting insert (12). The drill (6) comprises a cutting region (22) provided with grooves (14), wherein the grooves (14) extend helically and are formed between two grooves (14) drill backs (18). At least one of the drill backs (18) is partially flattened to form an adjustment surface (16) for the cutting insert (12), wherein the adjustment surface (16) extends helically. As a result, a length adjustment over a large length range is made possible independently of the twist angle (γ).