Abstract: A circular saw includes a base with an opening therethrough, a blade guard coupled to the base, and a saw blade at least partially positioned within the blade guard and extending through the opening of the base. The saw blade and the blade guard are pivotable relative to the base to adjust a bevel angle of the saw blade relative to the base. The circular saw also includes a housing supported by the blade guard, a motor positioned within the housing that is operable to rotate the saw blade, and a bevel angle guide coupled between the base and the blade guard. The bevel angle guide configured to indicate the bevel angle at which the saw blade is adjusted. The bevel angle guide is integrally formed with the base as a single piece.

Abstract: An improved offset saw blade mounting assembly for use on a reciprocating power saw tool includes a shim member that is used to fill a central slot of the tool drive shaft. The shim member fills the slot and serves to reinforce the drive shaft and thereby reduce the likelihood of the drive shaft failing. The shim member may be a separate piece, or formed as part of a separate tubular insert, or integrally formed with the mounting block of the offset mounting assembly. A finger guard is also provided that substantially closes off any opening which may occur between the mounting assembly and the power tool.

Abstract: A supporting and stabilizing shoe used with a masonry circular power saw. A shoe frame rigidly mounts to the saw's motor frame. A plate that is preferably substantially planar and bifurcated to form two substantially co-planar members with a gap therebetween pivotably mounts to the shoe frame. A spring biases the plate away from the blade, but can be overcome, and an adjustment knob tightens the plate in position relative to the blade. This provides for depth adjustment for the blade and keeps the blade at a desired angle, such as ninety degrees, to the workpiece surface. The plate extends longitudinally from the motor frame beneath the drive mechanism and the blade of the saw to provide a stable surface upon which the saw can rest during use or storage.

Abstract: A depth of cut scale is provided for a circular saw having a foot, a pivoting assembly (including a rotary saw blade) pivotably mounted to the foot, and a depth of cut adjustment mechanism operable to lock the pivoting assembly at a depth of cut (DOC) orientation relative to the foot. The depth of cut scale includes a shelf associated with and pivotable with the pivoting assembly. The shelf includes an upper surface bearing indicia indicative of DOC. An elongated element is fixed at one end relative to the pivoting assembly and includes a pointer adjacent an opposite end arranged to point to the indicia on the upper surface. The pointer is fixed in relation to the shelf as the shelf pivots with the pivoting assembly. The elongated element may be a flexible element that is maintained in tension overlaying the upper surface, or a cantilevered arm.

Abstract: A portable cutting machine is provided with a cutting machine main body, a surface plate rotatably supported by the cutting machine main body, a saw blade supported by the cutting machine main body rotatably around a first axis, and a lower guard supported by the cutting machine main body rotatably around a second axis. The first axis is located on one side of the surface plate. A part of the saw blade passes through an opening portion formed to penetrate through the surface plate and is exposed to the other side of the surface plate. The part of the saw blade exposed to the other side is covered by the lower guard. The first axis is parallel to the second axis. The first axis is located closer to a side of the surface plate than the second axis.

Abstract: A fastening apparatus for a limit stop element of an electric hand tool, in particular a hand circular saw, is disclosed. The fastening apparatus includes a guide, into which the limit stop element can be inserted and along which it can be displaced, and a locking mechanism, which can lock the limit stop element in the displacement direction. The locking mechanism has a spring element, which, in its locked position, clamps the limit stop element with a clamping force directed against the limit stop element and, in a released position, permits a displacement of the limit stop element.

Abstract: A shoe for a band saw includes a block for coupling to the band saw, the block having an aperture, a locking ball disposed in the aperture, a body including a first surface for engaging a workpiece and an opposite surface having plurality of recesses, and a locking rod coupled to the block and movable between a first position and a second position. The locking ball is received in one of the plurality of recesses of the body when the locking rod is in the first position such that the body is fixed relative to the block, and the body is movable relative to the block when the locking rod is in the second position.

Abstract: A power tool including a sliding member slidably received in the power tool and a pair of lock plates, each of the pair of lock plates including an opening, and the lock plates being configured such that the sliding member slides within the opening. First ends of each of the lock plates are pivotably attached to a support at a first side of the sliding member, and second ends of each of the lock plates being biased toward one another at an opposite side of the sliding member. A first contact portion of the lock plate contacts a first surface of the sliding member at the first side of the sliding member, and a second contact portion of the lock plate contacts a second surface of the sliding member at the opposite side of the sliding member, wherein the sliding member is secured with respect to the support.

Abstract: A support arrangement for a reciprocating tool comprises a first locking surface adjacent to an adjustable foot guide. The foot guide includes a second locking surface designed to mesh with the first locking surface in a locking engagement. The support arrangement further comprises a lock actuator including a first cam profile. The lock actuator is provided adjacent to a cam plate which includes a second cam profile. The second cam profile is configured to interact with the first cam profile and force the first locking surface toward the second locking surface of the foot guide. The lock actuator is moveable between an unlocked position and a locked position, wherein a first raised surface of the first cam profile does not engage a second raised surface of the second cam profile in the unlocked position, while the first cam surface does engage the second raised surface in the locked position.

Abstract: The present invention is an attachable rolling plate assembly which can be attached as a single unit to a portable cutting tool to facilitate the safe rolling movement of the portable cutting tool on the workpiece. The invention comprises a frame assembly formed from a single piece of molded material such as fiber enriched plastic having a pair of oppositely disposed longitudinal sidewalls with stabilizer fins extending therefrom, and a flat base portion having a pair of parallel stabilizer tubes molded therein. The invention further includes an adjustable bevel gear assembly by which the angle of orientation of the cutting blade can be quickly changed. The invention also includes a cutting guide assembly to facilitate a straight cut, reduce torsional rotation of the saw blade and reduce kickback of the saw.

Abstract: A reciprocating saw can include a housing and a motor disposed in the housing. A blade retaining mechanism can receive a saw blade. A drive mechanism can translate rotational motion of the motor into reciprocating motion of the blade retaining mechanism. A clamp assembly can include first and second shoes that are coupled to the housing. The first shoe can have a first shoe body that includes a first material facing surface. The second shoe can include a second material facing surface that opposes the first material facing surface and that defines a clamping distance therebetween. At least one of the first and second shoes is selectively adjustable relative to the housing, such that the clamping distance can be altered. One of the first or second shoe bodies can have a third material facing surface that comprises an arcuate section defining a radius.

Abstract: A portable cutting device capable of changing and adjusting a cutting depth of a circular saw blade relative to a base with lesser labor. A saw cover is pivoted on the base to change the cutting depth. An adjustment guide extends from the base in a pivotally moving direction of the saw cover in a superposed relation to the saw cover. A tightening unit is disposed to the saw cover at a position superposed with the adjustment guide and the saw cover for providing a selective tightening between the saw cover and the adjustment guide. The tightening unit includes a shaft part extending through the saw cover and the adjustment guide, a pivot operation part pivotally movable about an axis of the shaft part, and an urging part disposed over the shaft part and movable by the pivot operation part in the axial direction of the shaft part.

Abstract: A shoe for a band saw includes a block for coupling to the band saw, the block having an aperture, a locking ball disposed in the aperture, a body including a first surface for engaging a workpiece and an opposite surface having plurality of recesses, and a locking rod coupled to the block and movable between a first position and a second position. The locking ball is received in one of the plurality of recesses of the body when the locking rod is in the first position such that the body is fixed relative to the block, and the body is movable relative to the block when the locking rod is in the second position.

Abstract: The present invention provides a plunge-cut action circular saw having a double pivot hinge mechanism. Problems associated with this hinge mechanism, in particular axial end flow are reduced by urging a component of the hinge against a fixed component of the saw, such as a base plate component or the like. The urging force is applied by a resilient member, such as a spring washer.

Abstract: The invention is based on a hand-held power tool device, in particular a jigsaw device, having an adjusting device, which is equipped with a lever element and a mounting element for accommodating the lever element. As proposed in the invention, the mounting element is composed of a one-piece element extending 360° around an adjustment axis of the lever element.

Abstract: A tool trolley or guide for the precise control of hand held power tools such as a circular saw, saber saw, router or other portable power tool to guide the tool along a straight guide path. A chassis upon which the power tool is attached has a trolley like connection with a guide rail releasably secured to a work piece. The chassis has an opening through which the cutters of the tool extend. Tools are mounted on mounting plates which in turn are releasably mounted on the chassis.

Abstract: A saw for undercutting door jambs or trim including a saw blade attached to a flange having a first portion attached to the saw blade, a second, offset portion that extends away from a plane defined by the first portion and a third portion that extends away from the second portion in a plane generally parallel with the first portion. The third portion of the flange has a saw attachment portion for use with a general purpose saw.

Abstract: A movable handle and a power tool. The power tool comprises a housing, a motor supported by-the housing and operable to drive a tool element about an axis, and a handle supported by the housing for rotation relative to the housing about the axis. Preferably, the power tool is a circular saw. The circular saw further comprises a switch assembly supported on the handle for movement with the handle and means for connecting the switch to the motor to accommodate movement of the switch relative to the motor. The switch assembly is electrically connectable to the motor and selectively connects the motor to a power source, and the connecting means includes a wiring arrangement. The circular saw further comprises a locking assembly for locking the handle in a position relative to the housing.

Abstract: A portable circular saw has a housing and a baseplate. The housing carries a motor which is connected to a blade through a transmission mechanism. The baseplate includes a main baseplate and a secondary baseplate each of which has a bottom surface and the bottom surfaces are coplanar. At least a part of the blade passes though a slot formed in the main baseplate. The main baseplate includes a first edge and a second edge disposed on opposing sides of the blade. The secondary baseplate has at least two exchangeable positions. In a first position, the secondary baseplate is jointed or adjacent to the first edge of the main baseplate and, in a second position, the secondary baseplate is joined or adjacent to the second edge of the main baseplate.

Abstract: A motor-driven saber saw includes a guide device releasably connectable with the saw housing (11) in a region of the neck (13) and including a guide element (21) for guiding the saber saw (10) over a workpiece, a connection device (22) for connecting the guide element (21) to the housing (11) and having at least one connection part extending along an axis (A) and connectable with the neck (13), with the guide element (21) being supported on the at least one connection part (24) for displacement along the axis (A), and with the guide device (20) further including at least one spring element (27) located between the at least one connection part (24) and the guide element (21).

Abstract: A reciprocating saw includes a locking mechanism for a shoe of the reciprocating saw. The mechanism includes a lever mounted on the saw body movable to a first position where the saw blade is clamped in place. It also includes a lock pin with a body, a reduced circumference section, and a pin shoulder adjacent the reduced circumference section. The pin has a locked position where the pin shoulder abuts the shoe shoulder whereby the pin locks the shoe in place and an unlocked position where the shoe shoulder may translate through the clearance defined by the reduced circumference section. The lever urges the pin toward the locked position when the lever is in the first position.

Abstract: A base plate (20) for a power scroll saw is disclosed, which has a through opening (15) for a saw blade (13) that is drivable in a reciprocating motion by the power scroll saw. To prevent defective straight cuts and laterally obliquely extending cuts, especially in thick material to be cut, from lateral deflection of the tip of the saw blade in sawing, a guide device (21) with guide elements (22, 23) protruding into the through opening (15) is integrated with the base plate (20). With power scroll saws that have no guide device for laterally guiding the saw blade (13), an improved outcome of sawing can be attained by simply replacing its base plate for the novel base plate (20) disclosed here (FIG. 2).

Abstract: A movable handle and a power tool. The power tool comprises a housing, a motor supported by the housing and operable to drive a tool element about an axis, and a handle supported by the housing for rotation relative to the housing about the axis. Preferably, the power tool is a circular saw. The circular saw further comprises a switch assembly supported on the handle for movement with the handle and means for connecting the switch to the motor to accommodate movement of the switch relative to the motor. The switch assembly is electrically connectable to the motor and selectively connects the motor to a power source, and the connecting means includes a wiring arrangement. The circular saw further comprises a locking assembly for locking the handle in a position relative to the housing.

Abstract: A portable cutting tool includes a base and a tool main body which are inclinably connected such that a saw blade can be projected from a vicinity of an intersection between a side face of the base and a lower face of the base. A parallelism between the saw blade and the side face of the base is made to be able to be adjusted.

Abstract: A cutting tool that improves operability by facilitating operation of a lever for operating a clamp mechanism of a guide member is provided. A clamp mechanism is constituted by a clamp pin that protrudes its distal end to the outside of the blade case while penetrating a depth guide and the blade case, a first lever that is connected to the distal end of the clamp pin and directly moves the clamp pin in the axial direction, and a second lever that is connected to the upper portion of the first lever through a connecting pin and has a cam lever. When the second lever is rotated toward the blade case, the cam lever presses the connecting pin to tilt the first lever, whereby the clamp pin is pulled outward. As a result, the depth guide is pressed to the inner surface of the blade case and clamped.

Abstract: A movable handle and a power tool. The power tool comprises a housing, a motor supported by the housing and operable to drive a tool element about an axis, and a handle supported by the housing for rotation relative to the housing about the axis. Preferably, the power tool is a circular saw. The circular saw further comprises a switch assembly supported on the handle for movement with the handle and means for connecting the switch to the motor to accommodate movement of the switch relative to the motor. The switch assembly is electrically connectable to the motor and selectively connects the motor to a power source, and the connecting means includes a wiring arrangement. The circular saw further comprises a locking assembly for locking the handle in a position relative to the housing.

Abstract: An reciprocating saw comprising a housing, a motor, a spindle movably supported within said housing and having a front end adapted to support a saw blade, a drive assembly, and an adjustable shoe assembly. The adjustable shoe assembly includes a shoe, a shoe support member pivotally supporting the shoe, a locking member pivotally supported by the housing, and a lever connected to the locking member.

Abstract: A movable handle and a power tool. The power tool comprises a housing, a motor supported by the housing and operable to drive a tool element about an axis, and a handle supported by the housing for rotation relative to the housing about the axis. Preferably, the power tool is a circular saw. The circular saw further comprises a switch assembly supported on the handle for movement with the handle and means for connecting the switch to the motor to accommodate movement of the switch relative to the motor. The switch assembly is electrically connectable to the motor and selectively connects the motor to a power source, and the connecting means includes a wiring arrangement. The circular saw further comprises a locking assembly for locking the handle in a position relative to the housing.

Abstract: A power saw includes a body (36) housing a motor (24). The motor drives a reciprocal shaft (2) on which a blade (12) is mounted. The body is coupled to a pivotable sole plate (48,50) which is held relative to the body (36) in a plurality of positions such that in at least one position the sole plate may act as a guide for use of the tool as a jigsaw.

Abstract: A guide device for a hand held circular saw having a base, the device having a platform on which the base of a hand held circular saw can rest, wherein cooperating shoulders on the platform and saw base provide a guide for cutting on a straight line through a workpiece, wherein elevation flanges are provided on the sides of the platform and are provided with mounting structure which is operable to fix the platform to a supporting structure at a desired height above the workpiece, and wherein angle adjustment structure is provided on the elevation flanges for a fixing the angle of the platform and saw base with respect to the surface of the workpiece.

Abstract: Base seat of a pneumatic grinder, including an air way and a water way disposed in the base seat to respectively communicate with an air chamber and a water chamber formed in the base seat. Several water outlets and a predetermined number of air rooms are disposed on a bottom face of the base seat. The water outlets communicate with the water chamber, while the air rooms communicate with the air chamber. Multiple ball bodies are respectively rollably disposed in the air rooms, the bottom edge of the ball bodies protrude from the bottom face of the base seat. When high pressure air and water are conducted into the air way and water way, the air is conducted by the air way to flow into the air chamber and to blow to the ball bodies in the air rooms making the ball bodies rolling easily. The water flows through the water way into the water chamber and then flows through the water outlets out of the bottom face of the base seat to reduce frictional force against the bottom face of the base seat.

Abstract: An apparatus having a foot, a reciprocating saw and a housing. Between the foot and the housing there are means for releasable mounting the foot on the housing, characterized in that the releasable mounting means have a first coupling member connected to the foot and, co-acting therewith, a second coupling member connected to the housing. The coupling members can be carried from a disconnected to a connected position by a relative displacement between the foot and housing.

Abstract: A circular saw including a frame, a drive means mounted to the frame coupled to a planar saw blade for rotation about a drive axis within a cutting plane and a base pivotably mounted to the frame about a first axis substantially parallel to the cutting plane and a second axis which is generally substantially parallel to the drive axis. In one aspect, the relative pivotal movement of the frame about the first axis is determined by a trim adjuster including disengageable position locator which is operable to provide a plurality of predetermined discrete engaged positions and a locking means for locking the position of the frame relative to the base over a continuous range of settings. The invention also provides a mounting assembly including a course adjustment means and a fine adjustment means to determine the pivotal movement of the frame about the second axis relative to the base.

Abstract: A portable circular saw providing high visibility to a cutting mark line and sufficient operability even in case of an angled cutting. A slant position fixing member upstands from a front side of a base, and a tiltable plate is provided pivotally to the base. A front end of a saw cover is connected to the tiltable plate by a pivot pin. A main body roratably supporting a circular saw blade is pivotally movable by a pivotal movement of the tiltable plate to change inclination of the circular saw blade relative to the base. The tiltable plate is positioned in confrontation with the slant position fixing member, and fastening unit fixes the tiltable plate to the slant position fixing member to maintain a desired inclination of the circular saw blade. The fastening unit includes a thread extending through an arcuate slot formed in the slant position fixing member and engaging the tiltable plate, and a lever fixed to one end of the thread.

Abstract: A floating bench saw guide for guiding a portable circular saw along a workpiece while sawing the workpiece, has a cradle for retaining a portable circular saw, a saw plane across the cradle, and a guide lip movably affixed to the cradle. A pair of gage blocks are affixed to the cradle along the saw plane. The gage blocks are advantageous for allowing the use of a straight edge for easily positioning the blade of a circular saw along the saw plane. In another feature of the invention, a pair of spaced-apart parallel rails are affixed to the cradle. The guide lip is movably affixed to the rails and is reversible relative to the saw plane. The guide lip overhangs its mountings to the rails such that it is positional relative to the saw plane over a distance which is longer than the length of the rails.

Abstract: In a chain saw having a sprocket (11), which is supported in rotary fashion in a housing (10) and is for a saw chain (12) guided on a guide (13), and having a chain tension device (14) for longitudinally moving the blade (13), which device has a cam (15) that moves the guide (13) and a rotating member (17) for rotating the cam (15), in order to preset a chain tension that is optimal for operation and is independent of the user, the rotary connection between the rotating member (17) and cam (15) is embodied as a detent overload clutch (18), whose detent overload force is set in accordance with the required chain tension (FIG. 2).

Abstract: An attachment for a reciprocating saw comprises an offset member mounted on the drive head of the saw and comprising a lateral extension which holds a saw blade clear of the saw body The attachment also comprises a guard member having a planar surface adapted to engage a wall, and a slot through which the saw blade extends. The guard member is pivotally mounted on the saw body at a point spaced from the drive head. The attachment facilitates making a saw cut in a surface adjacent an inside corner.

Abstract: A guide for guiding a power tool such as a circular saw has a planar deck, and two shoulders extending from opposed edges of the deck in diametrically opposite directions. The deck is provided with mounting fasteners for securely attaching the saw to the guide. There is an aperture in the deck for receiving the circular saw, the aperture being off center. By attaching the power tool to opposite sides of the guide it is possible to obtain straight cuts of different widths.

Abstract: Hand-held appliance for preparation of an excised skin graft, that is placed upon a plane surface, by tangential excision of tissue below the epidermis to produce a trimmed skin graft of desired remaining tissue layers and thickness with a blade that is held between two holding rods, that can be placed on a plane surface and that is held in a height-adjustable axis parallel to the surface. The end regions of the rods are shaped so that the distance between the axis and the contact surface of the edge of the end regions to the surface changes at least by sections, while the minimal distance and the maximal distance define the lowest and the highest cutting plane, respectively, so that the distance of the cutting plane is defined by the operating angle between the plane of the rods and the surface.

Abstract: A machine tool, with a stop plate (2, 21), a working unit having a disk-shaped cutting tool (1, 17) and a driving mechanism (3), is connected pivotally with the stop plate (2, 21) for making angular and miter cuts. By means of several connecting link guides (4), mounted at the stop plate (2, 21), it is ensured that the cutting characteristics of the machine tool are independent of the pivoted position.

Abstract: The flush cut power saw comprises a framework having a base plate with a saw blade slot extending through two risers located at one end of the base plate. At least two rods slidably receive a movable housing for supporting a motor at a location above the cutting blade. The motor is secured to a transmission to convert the rotary motion of the motor to a reciprocating, linear motion. The transmission is connected to a saw blade mounting apparatus, which linearly reciprocates a cutting blade, which adjustably extends below the mounting plate. The cutting blade may be adjustably positioned with an adjustable stop for depth in vertical alignment with the framework. The transmission reciprocally biases the cutting blade, enabling the cutting blade to reciprocally travel linearly in relation with the movable housing, to complete a cut flush with an adjoining surface, while controlling the depth of cut.

Abstract: A cutting guide for use with a cutting device having a blade is provided. The cutting guide includes a bracket for securing the guide to the cutting device, a base connected to the bracket for supporting mounting stresses of the bracket, an ankle having a blade receiving and aligning slot and a flexure connecting the base to the ankle, thereby providing a cutting guide that can sustain high levels of force yet retain lateral flexibility. The width of the flexure is slightly greater than the width of the blade of the cutting device, thereby allowing the cutting device employing the cutting guide to cut any kind of material that would otherwise require a workbench.

Abstract: The present disclosure relates to a jigsaw including a base, a housing pivotally movable relative to the base about a first axis that extends longitudinally along the base, and a motor positioned within the housing. The jigsaw also includes a blade coupled to the motor by a drive mechanism adapted for reciprocating the blade in an up-and-down motion. The blade is laterally supported by a blade guide connected to the base that is pivotally movable about the first axis. When the housing is pivoted relative to the base about the first axis, the blade guide also pivots about the first axis to inhibit binding between the blade and the blade guide.

Abstract: A battery powered circular saw is provided with a novel motor housing and handle assembly having a rearwardly extending primary handle inclined 15° to 40° relative to a rearwardly longitudinally extending tubular housing member. A battery pack is attached to the rear end of the primary handle and is provided with an elongated projection which extends into the elongate tubular housing.

Abstract: A movable handle for a power tool. The power tool comprises a housing, a motor supported by the housing and operable to drive a tool element about an axis, and a handle supported by the housing for rotation relative to the housing about the axis. Preferably, the power tool is a circular saw. The circular saw further comprises a switch assembly supported on the handle for movement with the handle and means for connecting the switch to the motor to accommodate movement of the switch relative to the motor. The switch assembly is electrically connectable to the motor and selectively connects the motor to a power source, and the connecting means includes a wiring arrangement. The circular saw further comprises a locking assembly for locking the handle in a position relative to the housing.

Abstract: A portable circular saw is disclosed which includes a mechanism for simply and efficiently adjusting parallelism of the saw blade to the base. Two connecting members positioned at the front and rear of the saw connect the base of the saw to the saw cover, and the mechanism for adjusting parallelism is part of the front connecting member.

Abstract: A portable twin blade saw having adjustment for depth of cut of both blades and adjustments to ensure the saw blades are coplanar and parallel to a straight edge. The twin blade saw comprises a slotted main base (12) with a frame base (14) pivotally attach thereto. The saw blades (68), (82) are mounted on an arm (18) which is pivotally mounted to a plate. The plate is slidably mounted to the frame base (14). The saw blades (68), (82) are both driven by a single motor (90) via a driving arrangement.

Abstract: A combination of a base attachment structure and a cutting tool, where the base attachment structure includes a connection bolt (8) inserted and movably fitted in an aperture (9a) formed in a curved plate (9) of a gear housing (2) and a cross-shaped slide aperture (11) formed in an arch-shaped projection member (10) extending from a base (7). The connection bolt (8) includes a first upper threaded portion (8a) having threads running in a first direction to form a left-handed screw, and a second lower threaded portion (8b) having threads running in a second direction, opposite to the first direction, to form a right-handed screw. The first threaded portion (8a) is fitted into a hole (12a) formed in a pressure plate (12), whereas the second threaded portion (8b) pierces into an aperture (13a) formed in an arch-shaped clamp plate (13) and is then screwed to a right-handed fixation nut (16).

Abstract: The combination of an extension to the shaft of a sabre saw that moves the blade forward of the gear box housing and a guide plate with plates on the end that will abut a transverse plane and channels that will allow the saw to slide forward on the guide plate against a spring bias to cut to the intersection of two planes.

Abstract: An electric motor operated hand circular saw has a base plate, a motor housing turnable relative to the base plate, an electric motor accommodated in the motor housing and having a drive shaft, a circular saw blade arranged on the drive shaft of the electric motor, and a pre-slitting abutment for adjusting a pre-slitting position of the saw blade in which the saw blade penetrates into a surface of a workpiece to be sawed by a limited pre-slitting depth.