Abstract: 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.

Abstract: The invention relates to a drilling tool having a large drill, in particular a core drill, in which a center drill is guided in an axially flexible or movable manner, with the axial movement of said center drill relative to said large drill being limited by at least one limit stop, wherein at least one pin that is supported on the large drill, the shaft thereof or a transition therebetween, extends toward the center drill, and the pin (24) is formed at an attachment body (26) comprising a contact surface (46) that abuts on a counter contact surface (52) of the drilling tool (10) and in particular has at least partially a larger lateral extension than the pin.

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 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: 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: A hole cutter for cutting a work piece, such as a wood and/or metal work piece, has a substantially cylindrical blade body defining a wall thickness within the range of about 0.032 inch to about 0.038 inch, and a cutting edge formed on one end of the blade body including a plurality of teeth defining an average tooth pitch within the range of about 3.5 TPI to about 5.5 TPI for cutting the work piece and forming chips therefrom. The substantially cylindrical blade body and cutting edge define an average tooth pitch to blade body thickness ratio of at least about 110.

Abstract: To provide a user-friendly core drill which, when forming a large-diameter cut hole by the core drill with respect to an object to be drilled, such as concrete, is able to easily form, for example, a chamfered portion or a countersunk portion with respect to an opening end portion of the cut hole. In a core drill comprising a base body including a shank and a drill core body including a drill cutting blade, a connection opening portion of the drill core body being attached to the base body, the connection opening portion of the drill core body is provided with a concave portion forming member including a large-diameter hole cutting blade, and the large-diameter hole cutting blade is provided outside the drill cutting blade in a radial direction of the connection opening portion.

Abstract: A hole saw having efficient slug removal preferably includes a saw cup, a shank portion and a pilot cutting device. A cutting surface is formed on an open end of the saw cup. The inside surface, outside surface and cutting surface of the saw cup are given a low friction treatment. A fluoropolymer resin coating is used for the low friction treatment. The friction treatment is applied by spraying thereof on the saw cup. The saw cup is then heated to a predetermined temperature for a set period of time. The low friction treatment is cured when the saw cup is used. The shank portion is attached to a closed end of the saw cup with any suitable fastening process. The shank portion preferably retains the pilot cutting device.

Abstract: A hole saw having efficient slug removal preferably includes a saw cup, a shank portion and a pilot cutting device. A cutting surface is formed on an open end of the saw cup. An inside surface of the saw cup is given a low friction treatment and preferably an outside surface thereof. The shank portion is retained on a closed end of the saw cup. The pilot cutting device is preferably a drill, but other cutting devices may also be used. A second embodiment of a hole saw having efficient slug removal preferably includes a saw cup, a shank portion and a pilot cutting device. The saw cup includes a prior art saw cup, at least two side openings and a cutting surface. The at least two side openings are formed through the prior art saw cup to remove a substantial portion of a side wall.

Abstract: The front cutting edge is provided with an inner front cutting edge connected with an inner lateral cutting edge and an outer front cutting edge connected with an outer lateral cutting edge. A front flank corresponding to the front cutting edge is provided with an inner front flank corresponding to the inner front cutting edge and an outer front flank corresponding to the outer front cutting edge. An inner front clearance angle of the inner front flank is set at a larger value than an outer front clearance angle of the outer front flank. Therefore, it is difficult for the hole cutter to be chipped, and its cutting performance is also good.

Abstract: Pilot drill with coupon retainer and hot tapping machine using the same that positively retains a coupon cut out by a hole saw. The pilot drill bit has a shank having a driving end for attachment to a drill driver and a cutting end having a cutting edge thereon, the cutting edge being sized to drill a hole of selected diameter through a workpiece, and a movable retaining finger mounted on the shank adjacent the cutting edge, the movable retaining finger having a first position fitting within the cutting diameter of the cutting edge and a second, extended position where a portion thereof lies outside the cutting diameter to retain on the drill shank a workpiece through which the drill bit may have drilled.

Abstract: A hole saw cap for a hole cutter, the cap includes a plate defining a substantially circular peripheral groove and an annular shelf extending radially outwardly from the peripheral groove, the peripheral groove has a recess and a threaded hole extending through a center of the plate. In addition, a hole cutter that includes a cap plate defining a substantially circular peripheral groove and an annular shelf extending radially outwardly from the peripheral groove. The peripheral groove has a recess. There is an elongated band forming an approximately circular shape with opposite ends of the band contacting each other. The band includes a base edge received within the circular peripheral groove in an abutting relationship with an inner edge of the groove and a weld region formed between the band and cap plate and fixedly securing the base edge of the band to the cap plate. The annular shelf of the cap plate extends radially outwardly of the base edge of the band.

Abstract: An arbor system includes an arbor, a clamp body of a power tool, a tightening feature and an optional snap feature. The arbor has a flanging feature, a thread and a number of circumferentially arranged driving pins. The clamp body is sandwiched between the arbor and tightening feature in a pressed contact with the flanging feature defining a releasable fix that is fully form fitting. Operational tilt and load torque are transmitted without affecting the tight-screwed interlocking between thread and tightening feature. A snap feature, in the form of a spring pin or a spring tongue of a sandwiched washer, may secure the tightening feature against inadvertent unscrewing. The snap feature and snap serrations may be configured as a ratchet such that the snap feature needs only be actuated during unscrewing of the tightening feature.

Abstract: The hole saw slug removal device is a device constructed to fit within a hole saw that provides for automatic ejection of waste slugs from within the hole saw. The hole saw slug removal device generally consists of two discs affixed on either end of a compression spring. The device is then inserted into the hole saw, and one disc retains the compression spring within the hole saw by locking onto the drill bit or against the inner surface of the hole saw. Upon operation of the hole saw, the spring compresses and the other disc is pushed down by the force of the sawing. After the sawing is completed, the spring decompresses, and the disc is pushed forward, automatically ejecting the waste slug that has become trapped within the hole saw. The slug removal device may lack one disc and instead be permanently affixed to a hole saw.

Abstract: A plug ejecting hole saw includes a cylindrical saw cup provided with front cutting teeth, and an end wall having therethrough a non-circular concentric aperture; and an arbor holder removably attachable to a saw cup that includes a collar slidably holding a body including a nose piece, that has a cross-section which fits congruently within the aperture, and a pair of longitudinal grooves, which slidably hold locking tabs biased forward by springs to abut transverse ribs in the nose piece. The longitudinal grooves intersect a pair of transverse grooves blocked by the tabs. Inserting the nose piece into a cup aperture and pushing it forward causes each tab to be pushed rearward in a longitudinal groove, unblocking the transverse grooves and allowing the nose piece to be rotated relative to the saw cup, each tab springing forward to block a transverse groove and thereby lock the arbor holder to the sawcup.

Abstract: A cutting tool for locating an axis in a first member and cutting a sized hole in a second member overlying the first member. The cutting tool includes a base assembly and a cutter assembly which may be used independently of the base assembly. The cutter assembly includes a guide member, a cutting blade and a handle structure with a face portion. The guide member is coupled to the handle structure and extends from the face portion. The cutting blade is coupled to the handle structure such that the cutting blade extends from the face portion and is spaced radially outward of the guide member. The base assembly has a base structure, a stem member and a pilot aperture. The base structure has a first side adapted to contact the second member and a distal side adapted to contact the first member. The stem member is coupled to the distal side of the base structure and is adapted to engage a hole in the first member to locate the axis in the first member.

Abstract: A self-piercing gutter outlet for connecting a downspout to a gutter. The self-piercing gutter outlet includes a tubular sleeve having open top and bottom ends. An outwardly radiating upper flange is extended around the sleeve at the top end of the sleeve. The bottom end of the sleeve has a serrated lower edge therearound.

Abstract: A trepanning tool for making holes having a plurality of tool insert holders with pockets wherein replaceable carbide tool inserts are secured by retaining screws, the inserts being positioned so that alternate tool inserts cut overlapping inner and outer portions of a leading surface. Spiral chip relief grooves are provided on the exterior of the trepanning tool to receive cuttings made by each tool insert and remove cuttings from the hole. A tool insert which is positioned to cut the inner portion of the leading surface may be angled to direct cuttings outwardly, toward an adjacent chip relief groove. The flanks of the tool insert holders are cut back to allow access to the retaining screw in the adjacent tool insert holder for tool insert replacement.

Abstract: A holesaw includes an arbor for supporting a pilot drill and a bell-shaped sawblade. The sawblade is attached to a lower threaded portion of the arbor. A pin support with at least one pin engages the top of the holesaw blade and is axially movable but not rotationally movable relative to the arbor. A clamping sleeve is threaded onto an upper threaded portion of the arbor. The clamping sleeve can be screwed down to press against the bell top of the sawblade. A spring may be disposed between the clamping sleeve and the pin support.

Abstract: A wood coring drill bit comprising a hollow tube having an internal bore (103) and an exterior (100) with equally spaced bodies (10) of substantially uniform width extending in a helical manner from a cutting end (10) of said drill bit, said bodies (10) defining equally spaced flutes (15) between the edges of adjacent bodies (10), each body (10) comprising a land (20) upstanding from a relief (21) at the leading edge of the body (10), a respective cutting face (12) and associated lip (25) being formed at the end of each body (10) at said cutting end. The wood coring drill bit is characterized by having three equally spaced bodies (10) and flutes (15) said cutting face (12) has an included angle which is preferably 125.degree. for hardwood and drywood and 112.degree. for softwood. The lip (25) has a lip clearance angle that is about 6.degree..+-.1.degree. , the lands (20) on the bodies (10) extend for an axial distance of about 65 mm.+-.

Abstract: A hole cutter having a body provided with first and second types of cutting teeth. The cutter facilitates the discharge of cutting chips during machining of a workpiece. The tooth depth of the left and right sections of each of the second type of teeth is smaller than that of the left and right sections of each of the first type of teeth. The tooth depth of the middle section of each tooth of the second type is greater than that of the middle section of each tooth of the first type. A linear flattening section is provided at the middle portion of a second blade edge of each tooth of the second type. The flattening section causes each cutting chip to be shaped in a strip-like manner when removed from the workpiece. This separates the ends of the cutting chips from each other and prevents the chips from becoming entangled to one another.

Abstract: A crown drill including a hollow cylindrical carrier body, which is formed of two coaxially arranged tubes connected with each other, and a cutting member attached to the carrier body and projecting axially beyond the leading end of the carrier body.

Abstract: A printed wiring assembly rework tool and method which eliminates the need to remove a component from the printed wiring assembly in order to isolate a component pin from one or more printed circuits in the printed wiring assembly. The rework tool is able to mill or cut away a plated through hole and/or the area of the printed wiring assembly immediately surrounding the component pin without removing the component. Using the rework tool, the operation continues until the rework tool has either cut to a sufficient depth in the printed wiring assembly to sever a particular electrical connection, or the tool has cut all the way through the printed wiring assembly in order to completely isolate the component pin. The rework tool includes a pilot hole which accommodates the component pin as the tool cuts into the printed wiring assembly.

Abstract: An adaptor for stable mounting of a rotating tool in a drilling machine is disclosed, said adaptor comprising a continuous shaft (1), provided in one end with means (2) for fastening in a drilling machine and in the other end with a thread (3) for mounting of the tool, and an element (4), which in relation to the shaft, is movable in axial direction and fixed in the rotating direction, said element being provided with at least one driving pin (5) placed parallel to the shaft, but radially spaced in relation thereto, at least one driving pin being able to engage into a corresponding hole of the tool, characterized in an abutting element, which at least partly can be displaced in axial direction and clamped against the tool.

Abstract: The present invention discloses an annular hole cutter particularly useful for cutting railroad rails. Railroad rails are extremely hard and normally require drills or cutters which have carbide inserts. The present invention provides uniquely designed cutter with an improved cutter geometry, flute design and thin wall construction to allow the annular cutter to be used with a lower horsepower drill motor making the drill motor portable resulting in a portable rail cutting system.

Abstract: A hole saw includes a mandrel having a central pilot drill bit having a tapered shank to facilitate removal of the plug and an annular cutting saw blade. A helical spring is preferred coaxially mounted between the saw blade and the pilot. The spring biases the plug as the hole is being cut and automatically ejects the plug from the saw. According to a presently preferred embodiment, the spring is a conically tapered helical compression spring. Additional embodiments of modified pilots are also provided wherein the pilot is stepped, fluted, bulged, stepped and fluted, tapered and bulged, tapered with a fluted bulge, and tapered with a fluted rectangular section. The hole saw of the invention is inexpensive to manufacture and easy to use. Depending on the choice of pilot and the material cut, the plug will automatically eject from the saw or will eject after tapping the saw.

Abstract: A cutting tool having spaced elongate teeth. The tool facilitates 1) the removal of cut particles from the surface to be cut thereby enabling efficient cutting particularly of deeper holes; and, 2) the removal of the center cut out portion from the cutting tool. The tool comprises: a pilot drill bit; an anchoring disk fixed to and around a rear central portion of the drill bit; a plurality of peripherally spaced elongate teeth each having a rear end portion held in the anchoring disk, and a front end portion having a cutting edge; a sliding guide disk slidably positioned around the drill bit and in front of the anchoring disk so that the elongate teeth are radially positioned thereby; bias means to bias the sliding guide disk in a forward position; and, retention means to prevent the guide disk from sliding forwardly on the pilot drill bit beyond the cutting edges of the teeth.

Abstract: An arbor for a hole saw includes a shaft and a plurality of pins having either bearing surfaces, drive portions or both for engaging the hole saw. The arbor further includes a fixed position flange and a locking plate located above the flange, to which the pins are connected. The saw is mounted to the arbor and has a cylindrical body portion having a closed end defined by a drive plate and an opposite end defining a cutting edge for performing sawing operations on a work piece. The drive plate includes apertures for receiving the drive portions of the pins which pass through holes in the flange. When assembled the drive ends of the pins extend through the holes in the flange and into the mating drive plate apertures such that the bearing surfaces on the pins engage and support the drive plate of the hole saw.

Abstract: A plug cutter has a main body portion having a longitudinal axis, shank portion extending axially from one end of the main body, and a plurality of blades extending axially from an opposite end of the main body. The blades are formed so that at least a portion of the inner surfaces thereof have a measure of radial relief with respect to the leading edges of the blades. A radial distance from the axis of rotation of the plug cutter to the leading edge of each blade is always less than the radial distance from the axis of rotation to any other portion of the inner surface. Accordingly, when a plug is being cut with the plug cutter, a gap is defined between an outer surface of the plug and the radially relieved portion of the inner surfaces.

Abstract: A hole saw comprises a cup with two cutting teeth positioned on the open end of the cup. The two cutting teeth are substantially diametrically opposed to one another to provide a balanced cutting engagement of the media and are spaced apart by a chord length of between about 45 to about 180 degrees. A pair of secondary gullets are positioned in the cup proximate to a forward cutting edge of the two cutting teeth. The secondary gullets have a predetermined depth and shape along a longitudinal axis of the cup to suitably remove debris from the cup during a portion of the duration of the hole cut. A plurality of raker teeth may be positioned on the chords defining the spacing between the cutting teeth. The raker teeth are disposed below the cutting teeth, approximately 0.030 inches to engage and move cutting debris formed by the cutting teeth.

Abstract: A tool for cutting holes in metal provides a shank defining at one end an arbor releasably carrying a circularly annular cutter that defines teeth at each cutter end which may be sequentially used to extend cutter life without sharpening. The annular cutter defines a plurality of spirally arrayed, inwardly extending flutes and alternating outwardly extending lands on both inner and outer sides to provide cutting edges on both cutter sides at each end. The lands are formed with buttress type sides angulated ten to sixty degrees to a radius passing therethrough steeper spiral arrays of lands and grooves are arrayed in shallower spirals with an angle of up to seventy degrees to the axis of the cutter to allow thinner wall construction in my cutter than in prior cutters. The thinner cutter wall allows definition of more cutting teeth than would thicker walls and the cutter configuration allows definition of stronger, more efficient teeth without gullets.

Abstract: A device for removing embedded or broken fastening implements from bone, comprises a cylindrical drill bit with a cavity extending internally from a distal end of the bit. The distal end further defines a cutting surface disposed about the opening to the cavity. The interior surface of the cavity defines has a decreasing diameter as one proceeds away from the opening in the distal end, and thus the cutting surface is formed where the radial thickness of the wall of the drill bit is the thinnest. The interior surface of the cavity is susceptible to a galling effect when frictionally engaged by the exterior surface of the fastening implement intended to be removed. The operator places the drill bit around the site of the bone containing the fastening implement to be removed and rotates the bit so as to cut into the bone around the exterior surface of the fastening implement.

Abstract: A spring loaded automatic plug ejector for hole saws which utilizes a spring 50 which is increasingly compressed while a hole is being drilled. Once the hole is drilled, the spring 50 decompresses and ejects the plug from the hole saw. The amount of spring tension applied to the plug is adjusted by varying the degree to which the spring is compressed.

Abstract: A drill bit includes a one-piece cylindrical drill bit tube having a longitudinal axis and defining cylindrical surfaces including an inner cylindrical surface and an outer cylindrical surface. At least one of the cylindrical surfaces is configured to include deformations comprising at least one of embossments and recesses, all of the deformations appear over an entire length of the tube. At least some of the deformations are finite over the at least one of the cylindrical surfaces, the deformations further being adapted to stiffen the tube in the longitudinal direction without additional material reinforcements being disposed on the tube. The drill bit further includes hard-metal cutting elements disposed on a front face of the tube.

Abstract: A hole saw with wood removal feature comprised of a drill portion having a cylindrical engagement portion secured thereto. The cylindrical engagement portion has two projections on a lower surface thereof. The device includes a cylindrical hole saw portion having a planar upper end, an open lower end, and a cylindrical side wall therebetween. The planar upper end has a central aperture formed therethrough and a pair of small apertures being diametrically opposed from each other outside of the central aperture. The central aperture receives the drill portion therethrough with the two projections coupling with the pair of small apertures. The open lower end opens into a hollow interior cavity. The open lower end has a plurality of cutting teeth formed on an outer edge thereof. The cylindrical hole saw has an angular slot formed therein extending from the open lower end to a position beneath the planar upper end.

Abstract: A cylindrical cutter for use with a power drill including a base, a cylindrical wall extending from the base, a plurality of cutting teeth, and a plurality of raker teeth with one raker tooth positioned adjacent a cutting tooth.

Abstract: A hole producing assembly for a power drill including an adapter having one end operationally connected to the power drill such that the power drill rotates the adapter about an axis of rotation, the other end of the adapter includes a threaded shaft having threads that are of the four-start type, a cutter which has threads thereon that are complementary to the four-start threads on the adapter so that the cutter is threadably connectable to the adapter, the cutter has a cutting projection extending from the base and terminating in a cutting edge, and a spacer positioned between on the shaft of the adapter to aid in removal of the cutter from the adapter after use.

Abstract: A hole cutter (10) suitable for quickly cutting relatively large holes through wood, fiberboard, drywall and similar nonmetallic construction materials has a tubular member (16) attached to a back plate (14). The back plate includes attaching holes (22, 24) for attachment to a conventional hole saw arbor (12). The tubular member includes a gullet (28) which has a cutting bit (34) mounted adjacent thereto and facing in a direction of rotation. The cutting bit quickly cuts through wood and other materials. Chips generated during cutting are rapidly discharged away from the cutting edge (36) of the cutting bit and may pass through the gullet. Once the hole cutter has cut through, a core, which is cut out using the tool, is rapidly removed from the interior area (40). This is accomplished by using a screw driver or other tool extending through the gullet and prying out the core.

Abstract: A hollow annular drill bit is formed of an axially extending hollow cylindrical carrier member (1) and cutter members (2). The cutter members (2) are secured in recesses (1c) in the carrier member, so that they project axially from and radially inwardly and radially outwardly from the leading end region of the carrier member. The carrier member (1) has increased wall thickness sections enclosing the recesses, whereby sufficiently large connecting surfaces are available for securing the cutter members (2).

Abstract: A hollow crown drill has a set of cutting members (2, 3, 4) positioned on the leading or cutting end of an annular axially extending carrier member (1). The radial width of the cutting faces (2a, 3a, 4a) of the cutting members (2, 3, 4) increases opposite to the rotational direction (D) of the carrier member (1). In addition, the cutting members (3, 4) in the set disposed counter to the rotational direction (D) are offset in the direction parallel to the axis of the carrier member relative to the cutting member of the set leading in the rotational direction. This dimensional feature relates to the increase in the size of the cutting faces (2a, 3a, 4a). With the cutting faces (2a, 3a, 4a) dimensioned as above, each of the cutting members penetrates deep into the material being drilled, so that if the usual contact pressure forces are applied abrasive wear resulting in premature failure of the hollow crown drill does not occur.

Abstract: Rigid foam material, for example, expanded polystyrene foam, is drilled using a bit that forms an annular slit in the foam material and compresses the block temporarily around the slit. This frees the core for ready removal. The drill bit has a cutting ting at the leading end with an inside cutting edge and an annular bevel leading from the cutting edge to the outside surface of the cutting ring. The cutting ring is mounted on the leading end of a tube with an inside diameter greater than the inside diameter of the cutting ring in order to clear the core and an outside diameter less than the outside diameter of the cutting ring in order to clear the surrounding foam material.

Abstract: A cutter shell for cutting a circular opening in a metal object formed of a unitary metallic member having a tubular boring portion and an inverted dish shaped head portion. The boring portion has a tubular sidewall and teeth at the forward circumferential end. The sidewall is of thickness not greater than the teeth. The head portion has an outer circumferential perimeter secured to the tubular portion rearward circumferential end. The head portion has an inner concave surface as viewed through the tubular boring portion and an outer convex surface. The thickness of the head portion is not substantially greater than that of the boring portion tubular sidewall so that the head portion deflects inwardly in response to boring pressure, the deflection being radially transferred to the boring portion tubular sidewall to stiffen the sidewall and hold it in more perfect circularity during boring action.

Abstract: A retaining collar assembly for use with a hole saw arbor assembly. The arbor assembly includes a shaft, a hole saw attached to the shaft, a drive collar retained on the shaft for engaging the hole saw and a spring retained on the shaft. The retaining collar assembly includes a retaining collar which is retained on the shaft and abuts the spring such that the spring urges the retaining collar towards the drive collar. An axial limiting area is disposed on the shaft spaced away from the collar with a retaining collar rotating area disposed therebetween. The retaining collar rotating area allows the collar to rotate about the shaft while the axial limiting area only allows axial movement and not rotary movement. Protrusions and recesses are formed on the retaining collar and drive collar to prevent rotary movement of the retaining collar and drive collar relative to one another when the retaining collar is positioned in a retaining position.

Abstract: A tipped annular hole cutter is made by brazing all the cutting tips (30) simultaneously to the cylindrical wall (12) of the cutter body. The tips (30) have outer and inner lands (32, 34) which locate against the outer and inner surfaces (52, 54) of the cylindrical wall (12). This accurately locates the tips radially during brazing. The radially inner face (46) of the tip (30) is inclined so as to define an inner clearance face which has the necessary circumferential and radial clearances without therebeing any need to grind the inner face (46) after brazing.

Abstract: An improved annular hole cutter is disclosed that has a plurality of alternately arranged first and second cutting teeth positioned at substantially equally spaced intervals about the distal end of the cutter body. All of the cutting teeth having angled bottom faces that are tapered at the same angle towards a radially inner side of the bottom faces. The first cutting teeth each have a substantially straight leading edge that includes an active cutting surface and an inactive surface. The second cutting teeth each have circumferentially stepped inner and outer cutting edges. The relative axial heights of the cutting teeth are adjusted so that the active cutting surfaces of the first cutting teeth are formed at the same axial height as their radially corresponding cutting edges of the second cutting teeth. At the same time, the inactive surface of the first cutting teeth are formed at a different axial height than their radially corresponding cutting edges of the second cutting teeth.

Abstract: An annular hole cutter has a radially inner cutting tooth portion and a radially outer cutting tooth portion. Each of the inner and outer cutting tooth portions is formed with a flute for ejecting cut chips on the outer periphery of the cutter, and a cutting edge for radially outwardly pushing the cut chips. Therefore, the cut chips are smoothly ejected through the flute, and thus an annular hole is precisely cut at high speed.

Abstract: A drilling tool comprises a holder unit adapted to be detachably mounted to a hand-held drive unit, and a hole saw unit detachably mounted to the holder unit, the hole saw unit including, as a unit, a cylindrical cutter and a center pin, the holder unit including, as a unit, a spring and a slider disposed to allow reciprocating motion of the center pin, whereby the drilling tool is able to constantly form an appropriate hole in a workpiece such as a thin iron plate, a thick iron plate, or a pipe having a round surface, and expandable components of the drilling tool are formed as a unit to allow for ready replacement.

Abstract: This disclosure relates to a drill including a base having a shank and a tubular core body provided with hole-cutting blades at the peripheral edges of both openings, which are coupled together via a coupling ring between the base and the end of one of the openings of the core body, allowing the selective use of both sets of the core body's hole-cutting blades for hole cutting.

Abstract: A hole saw and drive includes a cup-shaped saw body having a closed end and a plurality of cutting teeth. A left-hand threaded collar is secured to the closed end and defines one or more drive tabs extending into the saw body interior. A left-hand threaded mandrel is received within the threaded collar and includes a pilot drill and intermediate outwardly extending flange. An additional set of one or more drive tabs extend upwardly toward the threaded collar from the flange. The drive tabs cooperate to couple rotational power from the mandrel to the saw body. The left-hand threads on the mandrel and collar cooperate to permit the reverse rotational operation of the mandrel to expel a cutting plug from the saw body interior.

Abstract: A cutting tool and method for cutting multidirectional cuts in a workpiece. The cutting tool has a body portion having a generally cylindrical outer wall and inner periphery. A plurality of cutting teeth are spaced circumferentially around the lower end and a plurality of flutes extend upwardly around the outer periphery from the lower end. The cutting teeth include a plurality of generally radially extending cutting edges positioned about the face of the cutting tool, a plurality of inside diameter cutting edges formed at the line of intersection of the radially extending cutting edges and the inner periphery of the cylindrical wall, and a plurality of outside diameter cutting edges formed at the line of intersection of the radially extending cutting edges and the outer periphery of the cylindrical wall.

Abstract: In one embodiment, the bodies of the mandrel and the drill have radially opposing portions thereof which are threadedly engaged about the axis of the drill. Through bores in the respective body portions make it possible to latch the drill to the mandrel for the drilling operation, using a pin that is inserted through the bores, and then when the drilling operation is completed, withdrawn from the bores to enable the core of work material to be ejected from the drill by advancing the mandrel on the threading while the drill is restrained against rotation. In other embodiments, the bodies of the mandrel and the drill have axially opposing portions thereof which are equipped with raised steps on the axially opposing faces thereof. The steps enable the drill to be latched to the mandrel for the drilling operation by engaging the faces of the body portions with one another so that the steps abut in one axial plane of the drill.