A hole saw includes a cylindrical body having a sidewall with a first end and a second end opposite the first end. The cylindrical body includes a gullet formed in the sidewall between a leading surface, a trailing surface, and a bottom surface of the sidewall. The gullet defines a central longitudinal axis extending between the first and second ends of the sidewall that is obliquely oriented relative to a rotational axis of the hole saw such that the gullet is angled from the first end to the bottom surface in a direction toward a cutting direction of the hole saw. The gullet has a dimension measured parallel to the rotational axis between the first end of the sidewall and the bottom surface of the gullet that is greater than 1.5 inches. The hole saw includes a cutting tooth coupled to the first end of the sidewall adjacent the gullet.

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 having a sidewall with a first end and a second end opposite the first end. The cylindrical body also includes a gullet formed in the sidewall between a leading surface, a trailing surface, and a bottom surface of the sidewall. The trailing surface defines a portion having a first radius. The bottom surface has a second radius. The first radius is larger than the second radius. The hole saw also includes a cutting tooth coupled to the first end of the sidewall adjacent the gullet.

A drill bit has a cutting portion having an annular portion, where the annular portion has a first end on which is disposed a cutting element and a second end that includes an outer insertion element and a stop shoulder. The drill bit has a drill shaft portion having a cylindrical drill shaft, where the drill shaft has an inner insertion element with an end face on a side of the drill shaft facing the cutting portion. The outer insertion element and the inner insertion element together form a plug connection in an insertion direction that is parallel to the axis of rotation and the insertion elements are connectable to each other via a pin element that is movable into a slot-shaped recess. The pin element is attached to an outside of the inner insertion element and the outer insertion element has the slot-shaped recess.

A flat flywheel body fabricated by water jet cutting has radial spoke pairs with a display hanger slot in between and flywheel weights circumferentially extending at their peripheral ends. Resilient thin attachment rims for the saw blades are circumferentially connecting the flywheel weights and provide together with them a continuous peripheral sliding surface. A two piece arbor is connected to a central continuous spline of the flywheel body. The peripheral saw blades are bent into concentric curvature by radially clamping them onto the blade attachment rims.

There is provided a cutting insert used for both drilling and turning. The cutting insert includes an insert main body having a front surface and a rear surface, the outline shapes of which are parallelogram shapes, peripheral side surfaces disposed on four sides of the insert main body, cutting edges provided on respective intersecting ridge lines between the front surface and the peripheral side surface and between the rear surface and the peripheral side surface of the insert main body, and a hole provided in the insert main body to incline with respect to the front surface and the rear surface, the hole being usable for attachment.

A drilling tool is configured to perform drilling and/or percussive work on materials such as stone, concrete and/or reinforced concrete. The drilling tool has a fastening region and a working region. The working region has a working body and at least one cutting element projecting axially and/or radially in relation to the working body. The at least one cutting element has at least one first cutting edge and at least one second cutting edge. The at least one second cutting edge is configured to serve as a replacement cutting edge and/or as an auxiliary cutting edge, and the at least one second cutting edge is set back, at least partly, in relation to the at least one first cutting edge of the drilling tool, axially along a longitudinal axis of the drilling tool, in a direction towards the fastening region.

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 surface-coated cutting tool includes a base material and a coating. A hard layer in the coating includes a plurality of crystal grains having a sodium chloride-type crystal structure. When the angle of intersection between the normal direction to (111) plane that is a crystal plane of the crystal grain and the normal direction to the surface of the base material is measured, a proportion A of the crystal grains having the angle of intersection of 0 degree or more to less than 20 degrees is 50% or more. The length of 3 grain boundaries is less than 50% of the length of 3-29 grain boundaries. The crystal grain has a layered structure in which a first layer and a second layer are alternately stacked. The total thickness of the first layer and the second layer adjacent to each other is 3 to 40 nm.

A drill bit has a cutting portion having an annular portion, where the annular portion has a first end on which is disposed a cutting element and a second end that includes an outer insertion element and a stop shoulder. The drill bit has a drill shaft portion having a cylindrical drill shaft, where the drill shaft has an inner insertion element with an end face on a side of the drill shaft facing the cutting portion. The outer insertion element and the inner insertion element together form a plug connection in an insertion direction that is parallel to the axis of rotation and the insertion elements are connectable to each other via a pin element that is movable into a slot-shaped recess. The pin element is attached to an outside of the inner insertion element and the outer insertion element has the slot-shaped recess.

A drill bit is disclosed. The drill bit has a cutting portion having an annular portion, where the annular portion has a first end on which is disposed a cutting element and a second end that includes an outer insertion element and a stop shoulder. The drill bit has a drill shaft portion having a cylindrical drill shaft, where the drill shaft has an inner insertion element with an end face on a side of the drill shaft facing the cutting portion. The outer insertion element and the inner insertion element together form a plug connection in an insertion direction that is parallel to the axis of rotation and the insertion elements are connectable to each other via a pin element that is movable into a slot-shaped recess. The pin element is attached to an outside of the inner insertion element and the outer insertion element has the slot-shaped recess.