Abstract: A drilling tool has a working piece retained by a retainer mounted to a collar. The working piece includes a distal shank and a cutting section and is rotationally fixed relative to the retainer. The retainer may include an engagement protrusion positioned outward of the shank with the protrusion engaging an inner surface of the collar or the collar may include an engagement protrusion with the protrusion engaging an inner surface of the retainer to create a quasi-floating relationship between the retainer and collar. The cutting section may have a distal primary bore cutting sub-section and a proximal counterbore cutting sub-section. The collar includes a lower surface for abutment against a building member during drilling operation to halt axial movement of the tool.

Abstract: An arbor for a hole saw includes an arbor shaft configured to be coupled to a power tool. The arbor shaft defines a longitudinal axis. The arbor also includes an arbor stem supported by the arbor shaft. The arbor stem includes at least one arm having a threaded portion configured to engage the hole saw. The arbor further includes an actuator supported by the arbor shaft. The actuator is operable to move the threaded portion of the at least one arm relative to the longitudinal axis.

Abstract: Wood core drilling bits for use in wood frame construction of structures in the residential and/or commercial market and sets of the same have a cylindrical barrel defining an axis of rotation and a first end that is open and a second end defined by a hub having a bore therethrough. The open end defines a plurality of cutting teeth and the cylindrical barrel defines a plurality of slots radially therethrough. The plurality of slots are positioned as points of a three-dimensional curve turning about the axis of rotation while moving parallel to the axis of rotation.

Abstract: A tool attachment, in particular hole saw, for a power tool having a driving axle that is drivable in oscillation. The tool attachment including a connecting device with which the tool attachment is attachable to the power tool such that the driving axle thereof and a tool axis essentially coincide. A work area has teeth, with the work area being at least partially circular in design and adjoining a hollow, cylindrical base. Openings are formed in the base, the openings constituting at least 60%, at least 80%, or at least 90% of the area of the base.

Abstract: A hole-saw comprises a tubular body connectable at one end to inter alia a power drill and formed at its other end with an annular array of cutting teeth. A collar is positioned at the end of the tubular body remote from the cutting teeth, the perimeter of the collar extending generally normal to and beyond the perimeter of the tubular body.

Abstract: An ultrasonic tip for fibrous tissue removal. The ultrasonic tip may be configured for at least torsional vibration and coupled to a distal end of a shaft of a surgical instrument with the shaft including a vibration conversion mechanism. The ultrasonic tip includes a plurality of slots extending between inner and outer circumferential surfaces to form a plurality of teeth. A depth of one of the slots at the outer circumferential surface is greater than a depth of the slot at the inner circumferential surface to define a sloped surface. The teeth include a cutting edge defined between the outer circumferential surface and a side surface defining the slot. The cutting edge includes a positive rake angle. The teeth may further include an inner cutting edge defined between the sloped surface and the inner circumferential surface with the inner cutting edge having a positive rake angle.

Abstract: 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.

Abstract: Provided are a hole formation method enabling the formation of a high-quality hole even when a workpiece material is a difficult-to-machining metal material or a fiber-reinforced composite material and a drill bit used in the method. A drill bit includes at least one cutting edge and a face (a leading flank and a trailing flank) positioned in the vicinity of the cutting edge, and on the face, a recess exhibiting a prescribed planar shape (groove) is provided. A hole formation method includes a hole formation step of machining a portion to be processed of a workpiece material by means of drilling to form a hole while a lubricant material for assisting machining process is in contact with the portion to be processed, and in the hole formation step, the drill bit is used.

Abstract: The present technology presents system of a guide for widening a drilled hole. In various embodiments the system comprises a hub including a circular central member and a plurality of slots for shims around a circumference of the circular central member. Embodiments include a plurality of shims with the plurality of shims being fit into the plurality of slots around the circumference of the circular central member. Furthermore, the plurality of shims each include a narrow end and a wide end with the narrow end of each of the plurality of shims being in a same direction and the wide end of each of the plurality of shims being in an opposite direction to the narrow end allowing for the guide to fit securely into the existing hole before drilling the new hole.

Abstract: An arthrodesis surgical method and apparatus. After a guide pin is inserted into the joint to be fused, a core saw creates a cored-out cavity in the joint to be fixated. An autograft bone core is harvested with a core saw and is inserted into the cored-out cavity. The joint is then immobilized for the healing process.

Abstract: An apparatus for ensuring proper location for a cutout in a sheet of construction material, to provide for access to an electrical box, includes an electrical box locator device with a body and at least one spike. The body mounts to the front opening of the electrical box and the spike projects perpendicularly relative to the plane of the electrical box opening such that it pierces the sheet of construction material and is visible on the side of the sheet of construction material opposite the side facing the electrical box once the sheet of construction material is positioned over the opening of the electrical box so as to help in locating a cutout in the sheet of construction material for the electrical box.

Abstract: This invention relates to a saw blade quick release mechanism for sawing tool and a sawing tool using same, the mechanism comprising a saw blade mount, a rotary cover rotatable on the saw blade mount, a resilient member holding the rotary cover in position, and a positioning component having a positioning member on either of the saw blade mount and the rotary cover and a positioning slot on the other one thereof whereby in case of the rotary cover positioned, the positioning member is at the positioning end of the positioning slot, and the saw blade cannot be disassembled then, while in case of the rotary cover disassembled, the positioning member is at a release end thereof, and the saw blade can be disassembled then.

Abstract: A cutting device in accordance with some example embodiments is provided for use with an arbor assembly. The cutting device includes a blade having a plurality of teeth, and a back plate at a proximal end of the blade. The back plate has an outer end surface in which a plurality of ramp surfaces and pin locking recess are provided. A central through hole extending through the back plate. The ramp surfaces only allow the cutting device to be rotated relative to the arbor assembly in one direction.

Abstract: Disclosed herein is an apparatus for processing a substrate that forms a hole in a substrate while reducing a burr in the hole so that a module device can be inserted into the hole to reduce the thickness of a display device, and the display device using the apparatus. The apparatus for processing the substrate comprises a body configured to operably be rotatable, and a cylindrical cutting tip at an end of the body. The bottom surface of the cutting tip is in an acute angle with respect to a contact surface of the substrate to allow formation of a groove at the substrate.

Abstract: A method and apparatus for treating tissue are disclosed, including intra-operative mapping of a probe ablation zone. The method uses a system that maps the proximal and distal margins of the probe ablation zone using tools that access the ablation target. In some embodiments, the tools comprise a bone drill, and an introducer assembly, including a cannula and a stylet. The tools have features or markings that cooperate to indicate which probe to use to achieve the desired ablation. The method further facilitates planning probe placement for delivering energy to treat (ablate) a desired ablation volume of a target tissue by using a system that maps both the target tissue and possible probe ablation zones.

Abstract: 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.

Abstract: A tool for roughening a borehole surface. The tool includes a coupling portion for clamping the tool; a tool head for machining the borehole surface; and an extraction duct. The coupling portion is disposed at a first end of a tool shank and the tool head at an opposite, second end of the tool shank. The tool head has a cutter disposed circumferentially on the tool heat The tool head has a slit, which passes through from one side to the other and which, starting from an end face of the tool head, extends axially along a longitudinal axis of the tool. The extraction duct extends at least partly axially along the longitudinal axis of the tool for extraction of drilling dust. The extraction duct, starting from the end face of the tool head, extends inside the tool shank and discharges circumferentially into a connecting opening in the tool shank.

Abstract: 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.

Abstract: Apparatus and methods are provided to penetrate a bone and associated bone marrow using a powered driver. The apparatus may include a housing; a drive shaft comprising a first end disposed within the housing and a second end extending from the housing, the second end of the drive shaft configured to releasably engage the intraosseous device; a motor disposed within the housing and rotatably engaged with the drive shaft; a rechargeable power supply configured to supply power to the motor; an electrical charging circuit configured to recharge the rechargeable power supply; and a visual indicator indicating a status of the rechargeable power supply. The apparatus may also include an electrical power circuit configured to measure one of torque and current flow through the motor.

Abstract: A tool for creating a wall opening. The tool includes a hole saw; and a centering jig having a center axis, where the centering jig is constructed as a centering ring, into which the hole saw can be pushed at least partly, and in that both the hole saw and the centering ring have on their circumference an opening such that this can be pushed transverse to the center axis completely onto a line.

Abstract: Disclosed herein is an apparatus for processing a substrate that forms a hole in a substrate while reducing a burr in the hole so that a module device can be inserted into the hole to reduce the thickness of a display device, and the display device using the apparatus. The apparatus for processing the substrate comprises a body configured to operably be rotatable, and a cylindrical cutting tip at an end of the body. The bottom surface of the cutting tip is in an acute angle with respect to a contact surface of the substrate to allow formation of a groove at the substrate.

Abstract: A method of machining a workpiece is provided that is capable of forming a fresh air inlet in an arbitrary position in an outer shell of a container. According to the present invention, a method of machining a workpiece is provided that includes: machining to form a round hole in a workpiece using a boring drill having a tubular end portion, the end portion provided with a flat surface and a notch, and having a blade on a side of the notch, by pressing the flat surface against the workpiece while rotating the drill to contact the blade with the workpiece.

Abstract: An apparatus for drilling a manhole includes a drill comprising a first motor and a drill bit. A rail extends longitudinally away from an exterior surface of the manhole. A carriage is movably engaged with the rail and is coupled to the drill. A mounting device supports the rail on an exterior of the manhole. The mounting device comprises features to transfer axial loading on the drill bit to the manhole. A method for drilling an opening in a manhole includes suspending a drill from a rail coupled to an exterior of the manhole. The rail extends laterally outwardly from the manhole. A drill bit forming part of the drill is rotated while moving the drill longitudinally along the rail toward the manhole. Axial reactive force generated by the drill is transferred to the manhole.

Abstract: A self-cutting, self-seating, self-securing electrical device is used for mounting lights and devices. It can be provided as an integral one piece box, with a saw ring blade provided as part of the round electrical work box, or the device can be provided without the built-in cutting saw ring blade, which is therefore provided as an add-on accessory which snaps into place within channel located along the top and channels on opposite sides of the downwardly extending round wall of the body of the self-seating electrical device. The self-seating electrical device also has two or more fasteners, such as three toggle swing clamps, to secure the electrical device in place in a cutout in a ceiling or interior or exterior wall panel, where the cutout is cut by the forward saw teethed blade edge of the electrical device.

Abstract: A method of reducing heat flow between IC chips and the resulting device are provided. Embodiments include attaching plural IC chips to an upper surface of a substrate; forming a lid over the IC chips; and forming a slit through the lid at a boundary between adjacent IC chips.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The disclosure is directed to a coil spring locking connector offering multiple groove geometries to allow multiple connection positions along the direction of insertion. A connector with an external spring access opening is formed through the housing wall surface. The opening allows access to the coil spring to allow removal of the spring from the connector prior to removal of the connector from a locked position to prevent potential damage to connector components.

Abstract: A surgical tool, enabling extraction of a prosthesis from a bony implantation site of that prosthesis, defines a proximo-distal axis and includes a distal end head adapted both to cut at least partially the bonding interface between the prosthesis and the bony material of the implantation site and to fix itself to the prosthesis by rotation centered on the proximo-distal axis, according to embodiments of the present invention.

Abstract: An assembly is provided for forming holes in a workpiece. The assembly includes an arbor, a pin sleeve and a cutting device. The arbor has a nose having at least one threaded portion and at least one unthreaded portions on an external surface thereof. The arbor also has at least one pin passageway extending therethrough. The pin sleeve has at least one pin extending from a main body. The arbor extends through the pin sleeve. The cutting device has a back plate and a plurality of teeth extending therefrom. The back plate has a passageway defined by a wall with at least one threaded portion and at least one unthreaded portion. The at least one threaded portion of the cutting device is capable of engaging with the at least one threaded portion of the nose, and the at least one pin of the pin sleeve is capable of engagement with the at least one pin passageway of the arbor to secure the components together.

Abstract: A texturizing tool that creates concentric, circular patterns of burrs in the surface of a workpiece by graving, planning or plowing, curved stop-grooves each with a burr of the displaced material which remains securely attached to the workpiece. Toothed cylindrical saws having angled slots for a drive pin are concentrically assembled. When forced against the workpiece, each saw rotates some few degrees causing the teeth to cut the stop-grooves and making the burrs. The drive pin and a return spring are carried in a capped outer cylindrical actuator which the drive pin also passes through. The concentric saw's cutting teeth cut in opposite directions to cancel out the cutting forces on the workpiece. Articles so texturized may be used in structural adhesive bonding, and for embedment of texturized articles such as fasteners, washers, plates and the like, into molded plastic and composite structures while being molded.

Abstract: The present invention relates to a hole-saw assembly includes a hole-saw having at one end a plurality of cutting teeth and with a boss attached to the hole-saw at the other end two shafts. The assembly includes a mandrel coaxially aligned with said hole-saw and including a body having two bores there through coaxially aligned with said shafts. An annulus located on top of the body is coaxially aligned with said mandrel and hole saw and includes two holes, the annulus rotatable around its longitudinal axis from a first to a second position. In the first position the annulus holes are aligned with the bores and shafts allowing the shafts to be freely insertable and removable and in the second position the holes are misaligned to lock the shafts to the annulus. The mandrel further includes a pair of driving pins adapted to engage driving apertures found in hole-saws especially larger ones.

Abstract: A drilling tool is disclosed. The drilling tool includes a drilling stub, a cutting element attached to the drilling stub, and a fastening section for fastening onto a tool holder. The fastening section is divided into at least one guide region and one locking region, where at least one interlocking geometry, which protrudes in the axial direction beyond the remaining locking region, and which in particular is a bulge, is designed for transmission of a torque from the tool holder to the drilling tool, and the at least one interlocking geometry has two abutting surfaces each in the tangential direction. One first abutting surface of the two abutting surfaces is designed essentially parallel to a longitudinal axis of the drilling tool and the first abutting surface serves to transmit the torque.

Abstract: The present invention relates to a hole-saw assembly (10) including a hole saw (26) having at one end a plurality of cutting teeth and at the other end two shafts. The assembly includes a mandrel (16) coaxially aligned with said hole-saw and including a body having two bores there through coaxially aligned with said shafts. An annulus (20) located on top of the body is coaxially aligned with said mandrel and hole saw and includes two holes, the annulus rotatable around its longitudinal axis from a first to a second position. In the first position the annulus holes are aligned with the bores and shafts allowing the shafts to be freely insertable and removable and in the second position the holes are misaligned to lock the shafts to the annulus. The mandrel further includes a pair of driving pins (22) adapted to engage driving apertures (24) found in hole saws especially larger ones.

Abstract: The present disclosure provides a pipe threading system including an adapter and an attachment for a handheld electric drill that applies a threading to the outer surface of a pipe. The system includes at least one dies shaped to cut a thread of the pipe. The attachment includes a central open bore to allow the threading of pipe sections beyond the length of the die's cutting surface.

Abstract: An assembly is provided for forming holes in a workpiece. The assembly includes an arbor, a pin sleeve and a cutting device. The arbor has a nose having at least one threaded portion and at least one unthreaded portions on an external surface thereof. The arbor also has at least one pin passageway extending therethrough. The pin sleeve has at least one pin extending from a main body. The arbor extends through the pin sleeve. The cutting device has a back plate and a plurality of teeth extending therefrom. The back plate has a passageway defined by a wall with at least one threaded portion and at least one unthreaded portion. The at least one threaded portion of the cutting device is capable of engaging with the at least one threaded portion of the nose, and the at least one pin of the pin sleeve is capable of engagement with the at least one pin passageway of the arbor to secure the components together.

Abstract: A core drilling machine having an axial extending hollow drill shaft supported rotatably in a housing and rotated by means of a drive unit; a coaxial tool holder receiving an axially displaceable drill bit, the tool holder having a locking mechanism securing the drill bit in a rotationally fixed manner to the hollow drill shaft; wherein the hollow drill shaft is suitable for receiving a shaft of an interchangeable centre drill, the center drill axially supported against a first spring element; and an axial stop element preventing in a first position a complete displacement of the center drill into the interior of the hollow drill shaft and allows in a second position a complete displacement of the center drill into the interior of the hollow drill shaft; and an activation device for activating the first or second positions of the stop element.

Abstract: A hole cutter has a substantially cylindrical blade body that defines an interior surface and an exterior surface that is located on an opposite side of the blade body relative to the interior surface. A cutting edge is located at one end of the blade body that generates swarf in cutting the work piece. A pattern is formed on the exterior and/or interior surfaces of the blade body. The pattern is configured to direct swarf generated at the cutting edge through the path and away from the cutting edge.

Abstract: A method of packaging a hole saw includes positioning a circular cutting edge portion of the hole saw against a surface of a base member of a hang tag assembly. The base member includes a post that extends from the surface into a hollow interior defined by the hole saw. A cap member of the hang tag assembly is positioned adjacent a mounting portion of the hole saw. The cap member includes a stem and a display card portion. The stem is advanced through a bore defined in the mounting portion and into the hollow interior of the hole saw. The post is then secured to the stem within the hollow interior of the hole saw.

Abstract: A support assembly for a core drill which utilizes an improved high strength spoked reinforcer. The reinforcer may be removably mounted a core drill tube by fasteners. A drive connection is removably mounted and centrally located on an outer disc of a pair of discs. The drive connection is adapted to connect with a drive shaft to cause rotation of the tube. The assembly can also include a split in the disc when the high strength spoked reinforcer is not welded thereto, thereby providing a means of water control. The high strength spoked reinforcer can be a separate piece that is bolted to the disc or can be integrally formed as one piece therewith.

Abstract: Cutting apparatus includes a pilot arrangement which has a tip. The tip engages a workpiece to form a pilot recess to engage the workpiece and prevent the apparatus skidding across the surface of the workpiece. The tip can retract against the action of a spring. Accordingly, the apparatus is prevented from skidding across the workpiece, but wear on the tip is minimized.

Abstract: An adjustable hole cutter for cutting a hole with a predetermined diameter in sheet or panel material includes a blade holder that moves along a track or slot to alter a diameter of the cut hole; a blade arc adjuster coupled to the blade holder; and one or more replaceable blade segments coupled to the blade holder.

Abstract: A cylindrical drill body for a hole saw has cutting teeth on an end side and at least one cutout, which is located in a lateral surface of the cylindrical drill body at a distance from the cutting teeth. The cutout has a rectilinear boundary edge directed parallel to the end side.

Abstract: A cutter assembly has an adapter, an outer collar, a recoil spring, a head, a pushing assembly and a central drill. The adapter has an L-shaped guiding slot and multiple balls. The outer collar is slidably and rotatably mounted around the adapter and has an annular protrusion and a positioning rod. The annular protrusion selectively abuts against the balls. The positioning rod is mounted on the outer collar and extends slidably into the guiding slot. The head is mounted detachably on the adapter and has a saw and an inserting rod. The inserting rod is inserted into the adapter and has an annular engaging groove. The annular engaging groove is formed around the inserting rod at a position corresponding to the balls to selectively hold the balls in the engaging groove.

Abstract: The hole saw apparatus cuts a hole in an existing work object such as drywall, for example. Floor and ceiling cuts as well as other hole cuts are also provided for. The apparatus enables a hole to be cut in the existing work object while guarding against electrical wire damage. The shank may be hexagonal and is chucked into an existing drill. Any existing wire is pulled through the guarded cylinder and even inserted into the sleeve if needed. The apparatus is then free to rotate around the wire and cut the desired hole. Upon completion of hole cutting, the apparatus is pulled away from the work object without damaging the wire. After cutting, a plug usually stays within a hole saw. The sliding mechanism of the apparatus provides for easily removing the cut plug from the hole saw.

Abstract: A power tool arbor assembly includes an arbor, an actuating member located at a second end of the arbor, and a friction member located at the second end of the arbor. The friction member is axially movable along the second end of the arbor. The friction member has a first axial position when no power tool accessory is attached to the second end of the arbor. The friction member is moveable toward a first end of the arbor from the first axial position to a second axial position in response to contact between the power tool accessory and the friction member, and the friction member is moveable toward the first end of the arbor from the second axial position to a third axial position when the actuating member is actuated.

Abstract: A hole includes a blade cylinder and at least one first blade portion and at least one second blade portion, which are arranged along the rotation direction at intervals. Each of the first and second blade portions includes an inside blade and an outside blade. In the first and second blade portions that are adjacent to each other along the rotation direction, the sum of the number of cutting edges of the outside blade and the cutting edge of the inside blade of the first blade is three or more, the sum of cutting edges of the outside blade and the cutting edge of the inside blade of the second blade is two or more, the number of the cutting edge of the first blade being different from the number of the cutting edges of the second blade.

Abstract: A system for repairing cartilage includes a trephine having a passage extending along a longitudinal axis of the trephine. The trephine has a distal end and a proximal end. The distal end includes a cutting member operable to cut a cartilage plug from a donor site. The passage is operable to receive the cartilage plug. Also, the trephine is flexible to selectively move between a first position in which the longitudinal axis is substantially linear and a second position in which the longitudinal axis is nonlinear. Moreover, the system includes a guide tool that is removably coupled to the trephine. The guide tool is operable to selectively move the trephine between the first and second positions. In addition, the system includes an ejector tool that ejects the cartilage plug from the passage toward a defect site.

Abstract: There is provided a drill bit comprising a bit body having a receptor portion formed therein, the receptor portion being filled with a cutting oil; a drilling portion extended from one end of the bit body, having a channel coupled to the receptor portion formed therein, and having an opening formed in one end thereof and connected to the channel; and a cutting portion provided at a periphery of the opening of the drilling portion for drilling a workpiece, wherein the channel of the drilling portion has a small diameter in order that the cutting oil is not discharged outside of the channel by external pressure or gravitational force, and the channel of the drilling portion has a structure in which capillary action occurs due to cut chips flowing through the channel during drilling of the workpiece so that the cutting oil may be discharged by the capillary action.