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.

One example of the present disclosure relates to a coupon. The coupon includes a first surface with a first circular channel and a second surface opposite and parallel to the first surface. The second surface is spaced a distance D0 from the first surface and includes a second circular channel concentric with the first circular channel. The coupon also includes a toroidal portion between the first circular channel and the second circular channel. The toroidal portion includes a rectangular sectional portion.

A core cutter includes: a cylindrical body; and a tipped bit that is disposed in a manner to protrude from a distal end of the body. The core cutter is configured to cut a workpiece with the bit when the body is rotated about a rotational axis that is an axis of the body. At a distal end of the body, a notch is formed adjacently to the bit at a position forward of the bit in a rotation direction of the body. A width of the notch in a circumferential direction of the body at the distal end of the body is less than or equal to 1.0 mm.

A hole saw including a cylindrical body with an outer wall extending along an axis of rotation from a cap end to a cutting end. The cutting end includes a plurality of cutting teeth disposed continuously around a circumference of the cutting end. The hole saw includes at least one elongated aperture disposed along the outer wall of the cylindrical body that is configured to receive a tool for removing one or more plugs from within the cylindrical body. The at least one elongated aperture has a first slot portion disposed adjacent to the cutting end and substantially parallel to the cap end, a second slot portion connected to the first slot portion at a first end of the second slot portion, and a third slot portion coupled to the second slot portion at a second end of the second slot portion opposite the first end.

A cutting tool comprises at least one cutting edge and at least one relief surface adjacent thereto. The relief surface is arranged to provide clearance behind the cutting edge between the cutting tool and a workpiece and comprises one or more grooves arranged to communicate, in use, a cutting media across the relief surface.

A method of producing a drill has a step of preparing a workpiece to be processed to produce a drill, and a step of forming a ground groove. The workpiece has a cutting blade, a chip discharge flute helically extending, and a rake surface which have been formed therein. The drill is rotated around a drill axial center. The formation step rotates a rotary whetstone around its whetstone axial center, and grinds the rake surface to form the ground groove along the chip discharge flute. The formation step uses the rotary whetstone so that the whetstone axial center intersects a longitudinal direction of the chip discharge flute. The rotary whetstone has a rotating body shape projecting in a radial outward direction of the rotary whetstone axial center and around the rotary whetstone axial center.

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.

The invention relates to single-lip drills in which two longitudinal grooves are formed in the rake face. They are arranged in the longitudinal direction of the tool, spaced apart from one another by a ridge and favor chip breaking.

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 μm.

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.