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 cutting tool with plug ejection includes a hole saw having a first central bore and an arbor having a second central bore along a central axis. The arbor is configured at one end to be coupled to a rotational drilling machine, and at the other end to be attached to the hole saw in a first cutting position and detached from the hole saw in a second ejection position. The hole cutting tool also includes a pilot guide having an ejection shoulder. The pilot guide is slidably disposed within the second central bore of the arbor and received through the first central bore of the hole saw. The pilot guide being configured to translate along the central axis between a first drilling position and the second ejection position.

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 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 combination system of fixed arbor hole saws and quick-change mandrel that enables a user to drill multiple of same sized or different sized holes in desired substrate in a quick and hassle-free manner. A drill bit held and retained in the quick-change mandrel serves as a common pilot for all different fixed arbor hole saws. The combo system requires a single common quick lock mandrel that positively locks a hole saw on insertion. The securely locked hole saw can be released with easy pull on a collar in the mandrel. Also, the cut-out slug of any substrate is very easy to remove once the hole saw is released from the mandrel.

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 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 safety drilling tool having a tapered drill bit that drills through materials, such as metal, without producing any torque or heat is provided. The safety drilling tool may provide safety for the operator of the tool while drilling or cutting into electrical/electronic enclosures, such as switchgear. The bit may include a smooth graduated cam on the cutting portion eliminate the usage of steps as is the conventional practice in the art. The drill bits may be different sizes to reduce the bulkiness for sake of convenience. The bits may have a one or more internal helical flutes for pushing the debris through the hole being drilled. The hole saw portion of the bit draws the material into the center of the bit until the initial hole is made allowing the debris from the tapered bit to flow through hole being drilled.

A hole saw assembly having a drive shaft, drive disk and hole saw blade. The drive disk has a plurality of radially extending projections that engage with engagement slots in the side of the hole saw blade.

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 hole saw with threadably removable portion is an improved hole saw that includes a removable portion that is able to slide back and forth with respect to an outer drill bit. The outer drill bit includes internal threadings along an inner surface, which correspond with external threadings provided on an outer surface of the removable portion. When the hole saw has bored a hole into an object, a core remains inside of the outer drill bit. The rotation of the drill rotates the removable portion with respect to the outer drill bit in order to push the core out of the outer drill bit. The outer drill bit includes a shoulder, which works in concert with the removable portion so as to lock the components together when in use as a hole saw.