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.

A drill bit, which is rotatable in a direction of rotation about an axis of rotation, is disclosed. The drill bit has a cutting portion with an annular portion where the annular portion has a first end on which is a cutting element and has at a second end a first insertion element. The drill bit has a drill shaft portion with a cylindrical drill shaft which has at an end, towards the cutting portion, a second insertion element. In a direction of insertion parallel to the axis of rotation, the insertion elements form a plug-in connection and can be additionally connected by way of at least one pin element which is movable in at least one slit-shaped clearance.

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 cutting tool includes a body having a cutting edge. A plurality of cutting teeth is formed on the cutting edge. Each cutting tooth includes a tip, a rake face extending from the tip, a planar primary relief surface extending from the tip, and a concave secondary relief surface extending from the primary relief surface. The cutting tool further includes a plurality of non-cutting protrusions formed on the cutting edge. Each non-cutting protrusion includes an apex, a leading edge extending from the apex, and a trailing edge extending from the apex. A plurality of primary and secondary gullets is formed on the cutting edge. Each primary gullet is formed between the secondary relief surface of one cutting tooth and the leading edge of one non-cutting protrusion. Each secondary gullet is formed between the rake face of one cutting tooth and the trailing edge of one non-cutting protrusion.

A hole cutter assembly is operable to cut a plurality of different sized diameter holes in a work piece. The hole cutter assembly includes an arbor configured to connect to a power tool for rotation about an axis, a drill bit coupled to the arbor for rotation with the arbor, a first arm moveable relative to the axis, a first cutting blade coupled to the first arm and moveable with the first arm, a second arm moveable relative to the axis, and a second cutting blade coupled to the second arm and moveable with the second arm. The first and second cutting blades are selectively moveable relative to the axis to adjust a cutting diameter of the hole cutter assembly. The drill bit engages the first and second arms to inhibit movement of the first and second cutting blades relative to the drill bit.

A pilot pin assembly is slidably receivable within a tool bit of a drill press. The pilot pin assembly includes a first pin defining an interior cavity, and a second pin at least partially received within the interior cavity of the first pin. A spring is positioned within the interior cavity for biasing the second pin toward an extended position relative to the first pin.

A hole cutter has a cylindrical blade body including a cutting edge and one or more axially-elongated apertures formed within a side wall of the blade body. The axially-elongated aperture is configured to receive a lever, such as a screwdriver, therethrough. Each axially-elongated aperture includes a first fulcrum axially spaced adjacent to the cutting edge, a second fulcrum axially spaced further away from the cutting edge than the first fulcrum, and optionally a third fulcrum axially spaced between the first and second fulcrums. A lever, such as a screwdriver, can be inserted into the aperture and placed against each of the fulcrums to lever slugs out of the interior of the blade body.

The disclosure concerns a system for hole drilling in an object (400) comprising a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400), where the core drill bit (200) is connected to the core drilling machine (100) and the core drilling machine (100) is equipped with a power source (108) in order to apply a rotating force to the core drill bit (200), and where the core drill bit (200) has an axially extending tubular shaft (202) with an inner envelop surface (203) defining an inner periphery (204) of the core drill bit (200), wherein the reaction bar (300) is non-rotatably connected to the core drilling machine (100) and arranged inside the inner periphery (204) of the axially extending tubular shaft (202) of the core drill bit (200). The disclosure further concerns a core drill bit (200) and a core drilling machine (100) for hole drilling in an object (400) and a method for hole drilling in an object (400) with a core drilling machine (100), a core drill bit (200) and a reaction bar (300) arranged for transmitting rotating reaction forces from the core drilling machine (100) to the object (400).

A system is disclosed for releasable coupling of a hole saw to a drill arbor. The system includes an elongate drill arbor configured at a first end to be clamped in a drill chuck of a drill, and a hole saw adapter provided with a longitudinal bore in which the drill arbor can be received so that an inner surface of the longitudinal bore of the hole saw adapter is mounted slidably on an outer surface of the drill arbor in the longitudinal direction of the drill arbor. The drill arbor includes an actuator member and at least one retaining element co-acting therewith. The inner surface of the longitudinal bore of the hole saw adapter is provided with a recess into which the retaining element of the drill arbor can protrude.

A hole cutter can include a cylindrical blade body with a cutting edge and one or more axially-elongated apertures. Each axially-elongated aperture can include a first fulcrum axially spaced from the cutting edge, and a second fulcrum axially spaced further away from the cutting edge than the first fulcrum. The blade body can also include a third fulcrum defined by a second aperture different from the one or more axially-elongated apertures. The third fulcrum may be spaced closer to the cutting than the first and second fulcrums. A lever, such as a screw driver, can be inserted into the apertures and placed against each of the fulcrums to lever slugs out of the interior of the blade body. The third fulcrum may alternatively be defined by another axially-elongated aperture that is located a different distance from the cutting edge than the axially-elongated aperture containing the first and second fulcrums.