A hole saw includes a substantially cylindrical body defining a cutting end and an axis of rotation. The hole saw also includes first and second apertures formed through the body and spaced from the cutting end such that a portion of the body extends between the cutting end and both the first and second apertures. The first and second apertures are both configured to receive a tool for removing work piece plugs from within the cylindrical body. The first aperture is axially spaced from the cutting end a first distance. The second aperture is axially spaced from the cutting end a second distance that is greater than the first distance. The first aperture and the second aperture are separated by a portion of the body.

A drill including: a chip discharge groove formed in an outer periphery of an edge portion serving as a leading end side portion of a drill body; and a cutting edge formed in an intersecting edge between a rake surface of a leading end side region and a leading end flank of the edge portion. The drill having a margin portion, a shoulder portion and a web thinning portion. The cutting edge includes, in order from a rotation center, first cutting edge, second cutting edge, shoulder cutting edge, and margin cutting edge portions. Honing widths of the second cutting edge, the margin cutting edge, and the shoulder cutting edge portions satisfy a relation represented by expression (1), as follows: honing width of the shoulder cutting edge portion>honing width of the margin cutting edge portionhoning width of the second cutting edge portion.

A drill device includes a drill tip and a drill body having a rear portion. The drill tip includes at least a first clearance surface and the drill body includes at least a first land having a margin. An edge is disposed between the first clearance surface and the margin. A textured area having a plurality of recesses extends along at least a portion of the margin, in the direction of the rear portion of the drill body, from a position of 200 m from the edge, from a position on the least first clearance surface, or from a position therebetween.

A general purpose hole saw guide and a method of forming holes through surfaces, without the need of a centering bit, are provided. The hole saw guide includes a circular disk with concentric grooves on its surface. The disk is transparent and portable for placement on a surface through which a hole is to be drilled to facilitate the centering and stabilizing control of a hole saw on the surface. The method includes the steps of providing a transparent disk having concentric grooves; positioning the disk on a surface; mounting the disk to the surface; inserting a hole saw that is fitted to a drill into the grooves of the disk; drilling a hole through the disk and surface beneath it; and removing the disk from the surface after the hole has been drilled.

A general purpose hole saw guide and a method of forming holes through surfaces, without the need of a centering bit, are provided. The hole saw guide includes a circular disk with concentric grooves on its surface. The disk is transparent and portable for placement on a surface through which a hole is to be drilled to facilitate the centering and stabilizing control of a hole saw on the surface. The method includes the steps of providing a transparent disk having concentric grooves; positioning the disk on a surface; mounting the disk to the surface; inserting a hole saw that is fitted to a drill into the grooves of the disk; drilling a hole through the disk and surface beneath it; and removing the disk from the surface after the hole has been drilled.

The drill has a rake face, a flank face, and an outer circumferential surface. The flank face is continuous to the rake face. The outer circumferential surface is continuous to both the rake face and the flank face. A ridgeline between the rake face and the flank face constitutes a cutting edge. A ridgeline between the rake face and the outer circumferential surface constitutes an outer circumferential end. A groove is provided cyclically in the rake face to extend at an angle relative to an axis of the drill, the angle being larger than a helix angle of the drill. The groove has a depth of more than or equal to 1.5 m.

A bore cutting tool for cutting metal workpieces includes a tool substrate and a tool coating on a surface of the tool substrate. The bore cutting tool includes a plurality of pits in the surface of the tool substrate and wherein the tool coating extends over the pits such that the pit surface includes the tool coating. In this way, the pit dimensions can be retained over prolonged tool life and the pits, with their coated surface, are particularly effective at retaining lubricant so that the thickness of a lubricant film can be increased as compared to a tool without the coated pits. In the embodiments, the pits are formed by laser etching and are present only on the cylindrical land. Average pit depth is suitably in the range 8 m to 25 m, average pit width and pit length is independently selected from 40 m to 250 m and average pit density may be 20 to 30 pits/mm.sup.2.

A hole cutter has a substantially cylindrical blade body defining a blade body circumference, a cutting edge formed on one end of the blade body, and an axially-elongated slot formed through the substantially cylindrical blade body. The axially-elongated slot is configured to receive chips flowing from the cutting edge within the interior of the blade body and (i) into the slot and/or (ii) through the slot, to prevent the collection of such chips within the interior of the blade body and/or at an interface between the blade body and the work piece. The axially-elongated slot defines a first end adjacent to the cutting edge, a second end axially spaced further from the cutting edge, and a slot area. The hole cutter further defines a total slot area to blade body circumference ratio within the range of about 0.1 to about 0.3 depending on the size of the hole cutter.

A hole saw is movable about a rotational axis in a cutting direction to cut into a workpiece. The hole saw includes a cylindrical body with a sidewall having a first end and a second end opposite the first end, a gullet formed in the sidewall between a leading surface, a trailing surface, and a bottom surface of the sidewall, and a support aperture formed in the sidewall. The gullet extends through the first end of the body. The support aperture is entirely surrounded by the sidewall. A majority of the support aperture circumferentially overlaps with the gullet. At least a portion of the support aperture is positioned closer than the bottom surface of the sidewall to the second end. The hole saw includes a cutting tooth coupled to the first end of the sidewall adjacent the gullet and an end cap coupled to the second end of the sidewall.

A hole cutter has a substantially cylindrical blade body defining a blade body circumference, a cutting edge formed on one end of the blade body, and an axially-elongated slot formed through the substantially cylindrical blade body. The axially-elongated slot is configured to receive chips flowing from the cutting edge within the interior of the blade body and (i) into the slot and/or (ii) through the slot, to prevent the collection of such chips within the interior of the blade body and/or at an interface between the blade body and the work piece. The axially-elongated slot defines a first end adjacent to the cutting edge, a second end axially spaced further from the cutting edge, and a slot area. The hole cutter further defines a total slot area to blade body circumference ratio within the range of about 0.1 to about 0.3 depending on the size of the hole cutter.