50 results about "Large tooth" patented technology

A kettlebell comprises a main weight block and several weight blocks, a teeth meshing plate is disposed on a top surface of the main weight block; a rotating shaft having an upper engaging rod and a lower engaging rod, the lower engaging rod optionally engages on the teeth meshing plate; a large teeth plate can move elastically, the large teeth plate is provided with first engaging teeth on a periphery of a through hole annularly; a connecting plate annularly provided with second engaging teeth movably meshing with the first engaging teeth, a lower end surface of the connecting plate is annularly provided with connecting teeth connected with the upper engaging rod. Positions of the connecting plate can be changed through the upper engaging rod, the main weight block can be fixed on the lower engaging rod, so that actions of the kettlebell can be switched reliably, and the rotating shaft can rotate freely without weight.

The utility model relates to the technical field of universal joint connection, and discloses a light-weight end tooth structure universal joint easy to align teeth, which comprises a rotation axis of the universal joint and an end tooth disc rotating around the rotation axis of the universal joint, a plurality of tooth parts are arranged on the end tooth disc along the rotation axis in a central symmetry manner, and the tooth parts are arranged on the end tooth disc. The tooth part comprises a tooth bottom arranged on the end-toothed disc, a tooth top is arranged at the top of the tooth bottom, symmetrical first tooth surfaces are arranged at the two opposite side ends of the tooth bottom, and symmetrical second tooth surfaces are arranged at the two opposite side ends of the tooth top. The second angle formed by the two second tooth surfaces on the tooth top is configured to be larger than the first angle formed by the two first tooth surfaces on the tooth bottom, the meshing tolerance range between the tooth parts is enlarged through the design, larger tooth alignment tolerance is allowed in the assembling process, and therefore the axial alignment operation of the gear and a matched piece is simplified, and the assembling efficiency is improved. And the adjustment frequency during assembly is reduced.

A gear shaper suitable for ultra-large tooth width machining comprises a lathe bed, a stand column, a cutter shaft and a workbench, a servo motor is adopted to drive a ball screw to serve as a main movement system, and a cutter rest sliding plate is driven to achieve accurate up-down reciprocating motion; the cutter shaft is rigidly connected with the sliding plate through an end face bearing and supported by hydrostatic bearings at the two ends, and the supporting distance L is larger than or equal to the tooth width * 2.5. The tool rest transmission system is integrated on the sliding plate and drives the tool shaft to rotate through a worm and gear pair. The radial feeding system drives a sliding seat to move through a servo motor and a ball screw; a workbench independent cutter relieving mechanism is innovatively adopted, and a servo motor drives a ball screw to achieve precise cutter relieving motion. According to the design, a traditional hydraulic system is abandoned, through a modularized multi-axis linkage structure, the mechanical layout is remarkably simplified, the machining precision and efficiency are improved, and the technical blank of large-modulus and ultra-long-tooth-width gear machining equipment is filled up.

The utility model discloses a stator small tooth pressure plate and an adjusting system. The stator small tooth pressure plate at least comprises but is not limited to a bearing part used for being connected with a machine base large tooth pressure plate, an inner concave part used for reducing polishing amount, and a top surface part used for being in contact with a pressure finger. The bearing parts are arranged on the two sides of the inner concave part; according to the scheme, the mode of machining the boss is adopted, gaskets do not need to be added, the problem that the gaskets are difficult to weld does not need to be solved, the risk that the gaskets fall off does not exist, and accurate adjustment of the flatness can be achieved by polishing the thickness of the boss.

The utility model discloses a synchronous transmission stabilizing device which comprises a minimum tooth piece arranged on the outermost side and a maximum tooth piece arranged on the innermost side, and a plurality of middle tooth pieces with the sizes gradually increased in sequence are arranged between the minimum tooth piece and the maximum tooth piece. A plurality of meshing teeth are evenly distributed on the circumference of the minimum tooth piece, the circumference of the middle tooth piece and the circumference of the maximum tooth piece, and a fixed track toothless tooth piece is detachably arranged on the side, away from the minimum tooth piece, of the maximum tooth piece. Through the optimized and improved design of the product, when a transmission medium such as a chain or a belt is located on the innermost maximum tooth sheet, the situation that the transmission medium is disengaged from the meshing surface is effectively avoided, the chain or the belt cannot be disengaged under the road condition or misoperation of a rider, and the service life of the chain or the belt is prolonged. And transmission media such as a chain or a belt can stably work in the current driving track, so that the effects of improving the safety, totally selecting driving and guaranteeing the personal safety of a user are achieved.

The utility model discloses a tooth aligning tool for machining duplex teeth, and relates to the technical field of duplex teeth. Comprising a tool disc, a placement ring is installed on the outer surface of the tool disc, three annularly-distributed positioning assemblies are installed on the outer surface of the tool disc, the positioning assemblies are used for positioning duplex teeth, a circular groove is formed in the outer surface of the top of the tool disc, and a fixing shaft is connected to the inner wall of the bottom of the circular groove through a bearing; the top outer surface of the fixing shaft is provided with a plug-in assembly. The large tooth of the duplex gear can be positioned through the three positioning assemblies, each positioning assembly drives the positioning block to position the large tooth through the air cylinder, one end of the positioning block is clamped between two gears of the large tooth, manual operation is not needed, the positioning efficiency is improved, the tool column can also rotate, and the positioning precision is improved. And after rotation, the annular electromagnet operates to attract a metal disc of the plug-in assembly, so that the tool column can be positioned, and different machining requirements are met.

A kettlebell comprises a main weight block and several weight blocks, a teeth meshing plate is disposed on a top surface of the main weight block; a rotating shaft having an upper engaging rod and a lower engaging rod, the lower engaging rod optionally engages on the teeth meshing plate; a large teeth plate can move elastically, the large teeth plate is provided with first engaging teeth on a periphery of a through hole annularly; a connecting plate annularly provided with second engaging teeth movably meshing with the first engaging teeth, a lower end surface of the connecting plate is annularly provided with connecting teeth connected with the upper engaging rod. Positions of the connecting plate can be changed through the upper engaging rod, the main weight block can be fixed on the lower engaging rod, so that actions of the kettlebell can be switched reliably, and the rotating shaft can rotate freely without weight.

The invention belongs to the technical field of mining hard alloy, and particularly relates to a mining hard alloy tooth and a passivation method thereof.The passivation method comprises the following steps that S1, a first mining hard alloy tooth and sodium phosphate are obtained; s2, the first mining hard alloy tooth, pure water and sodium phosphate are added into a passivation machine to be passivated, and then the mining hard alloy tooth is obtained; the first mining hard alloy teeth comprise large teeth and small teeth, the diameter of the large teeth is larger than 8 mm, and the diameter of the small teeth is smaller than or equal to 8 mm. The large teeth and the small teeth are matched, so that the contact area is increased, the passivation efficiency is improved, and meanwhile, the production efficiency is also improved; alkalescent sodium phosphate is selected as a passivating agent, so that an oxide layer and impurities of the hard alloy teeth can be removed, a layer of passive film is formed, and the surface quality of the hard alloy teeth is improved; and the interior of the passivation machine is surrounded by resin, and the softness of the resin prevents the hard alloy teeth from falling off edges and corners when poured into the passivation machine.

The utility model discloses a left-right difference ratchet wheel structure which comprises a handle body head, a center installation hole is formed in the middle of the top face of the handle body head, a lower adjusting groove extending backwards is formed in the inner side wall of the middle of the rear portion of the center installation hole, and an installation through hole extending upwards is formed in the bottom face of the rear portion of the handle body head. The ratchet head is inserted into the center mounting hole in a sleeved mode, an outer tooth part is formed on the outer side wall of the ratchet head, a pawl block is inserted into the lower adjusting groove in a sleeved mode, a tooth-shaped part is formed on the front wall face of the pawl block, the tooth-shaped part is matched with the outer tooth part, one half of the tooth-shaped part is a large tooth part, and the other half of the tooth-shaped part is a small tooth part. And the size of the large tooth part is twice that of the small tooth part. Half of a tooth-shaped part of a pawl block is a large tooth part, the other half of the tooth-shaped part of the pawl block is a small tooth part, and the size of the large tooth part is twice that of the small tooth part.

A multifunctional nail polishing head includes a grinding head and a grinding handle, a plurality of first helical grooves are defined on a circumferential wall of the grinding head at intervals, the grinding head is provided with a rack between every two adjacent ones of the plurality of first helical grooves, in a radial section of the grinding head, a plurality of sets of large tooth segment are formed along a circumferential direction of the grinding head, each set of the plurality of sets of large tooth segment consists of a plurality of racks, an arrangement density of the plurality of racks in one set of the plurality of sets of large tooth segment is from sparse to dense, or from dense to sparse, or alternates dense and sparse along the circumferential direction of the grinding head.

The application discloses a large internal ratchet wheel machining method, which comprises the following steps: S1, rotating a machine tool B shaft; S2, tooling a ball cutter (4) installed on the machine tool B shaft accessory with any two points on a large tooth surface of a tooling slot and any one point on a small tooth surface respectively to obtain coordinate values of each tooling point in a cutter tip coordinate system; S3, according to the intersection of a tooth root virtual circle under the cutter tip coordinate system and the connecting line of the two tooling points on the large tooth surface, the intersection point constitutes the coordinate values of a tooth root vertex in the cutter tip coordinate system, and the coordinate values of the tooth root vertex in the cutter tip coordinate system and the offset of the cutter tip coordinate system relative to a part coordinate system are obtained according to a trigonometric function relationship; and S4, the offset is used for compensating the cutter tip position deviation generated by the rotation of the machine tool B shaft. The technical effect of the application is that qualified large internal ratchet wheels are machined by compensating the cutter tip position deviation and the part tooth slot phase deviation, qualified large internal ratchet wheels are machined on a machine tool by using a common ball cutter, and production cost is saved.

The invention discloses an automatic tensioner assembly assembling system which comprises a shell assembling work station, a large tooth frame assembling work station, a guide block assembling work station, a small tooth frame assembling work station, a spring assembling work station and an assembly assembling work station. The large tooth frame assembling work station is suitable for assembling a large tooth frame into an inner groove of a shell to form a shell assembly; the small tooth frame assembling station and the spring assembling station are suitable for assembling the small tooth frame into an inner groove of the guide block and assembling the spring into the outer wall of the guide block to form a guide block assembly, and the assembly assembling station is suitable for assembling the shell assembly and the guide block assembly to form a tensioner assembly. The oil coating process of the outer wall of the guide block is set behind the spring assembly station, oil loss can be reduced, and the problem of oil contamination in a system is solved. And the spring can be compressed during oil coating, and the outer wall of the guide block is exposed when the spring deforms, so that direct contact is facilitated for oil coating.

The utility model discloses an embracing type bridging coupling oil pipe centralizer which is formed by oppositely splicing a front semi-cylindrical structural body and a rear semi-cylindrical structural body which are symmetrical in structure, the structural bodies are of an integrated structure, and the two structural bodies are clamped through a plurality of steel belts. Each structural body is formed by sequentially connecting a small tooth block, an upper closing groove, a large tooth block, a middle closing groove, a middle structure, a middle closing groove, a large tooth block, an upper closing groove and a small tooth block from top to bottom; and the small tooth block, the upper closing groove, the large tooth block and the middle closing groove are all semi-cylindrical. The outer diameters of the small tooth block, the large tooth block and the middle structure are equal, and the height of the small tooth block is smaller than that of the large tooth block; the sum of the outer diameter of the upper closing groove and the thickness of the steel belt and the sum of the outer diameter of the middle closing groove and the thickness of the steel belt are equal to the outer diameter of the middle structure. The whole structure is easy to achieve, convenient to install and not prone to displacement. In addition, the manufacturing cost is low, and meanwhile the device can still be repeatedly used after pump inspection and well repair.

The application belongs to the technical field of mining hard alloy, and particularly relates to a mining hard alloy tooth and a passivation method thereof, the passivation method comprising the following steps: S1, obtaining a first mining hard alloy tooth and sodium phosphate; S2, adding the first mining hard alloy tooth, pure water and the sodium phosphate into a passivation machine for passivation to obtain a mining hard alloy tooth; the first mining hard alloy tooth comprises large teeth and small teeth, the diameter of the large teeth is greater than 8 mm, and the diameter of the small teeth is less than or equal to 8 mm. The application increases the contact area and improves the passivation efficiency by matching the large teeth and the small teeth, and the production efficiency is also improved; the sodium phosphate with weak alkalinity is selected as the passivating agent, the oxide layer and impurities of the hard alloy tooth can be removed, a passivation film is formed, and the surface quality is improved; moreover, the passivation machine is surrounded by resin, and the softness of the resin prevents the hard alloy tooth from being poured into the passivation machine to cause edge and corner defects.

The utility model discloses a multi-punching-tooth riveting press forming gear, and relates to the technical field of gear machining and manufacturing, the multi-punching-tooth riveting press forming gear comprises a knurled shaft pin and further comprises a connecting mechanism arranged on the outer side of the knurled shaft pin, and the connecting mechanism can reduce cost while guaranteeing the strength of the gear. The multiple sets of large driven teeth and the multiple sets of small driving teeth are all arranged on the outer side of the knurled shaft pin in a sleeving mode, a traditional large tooth is evenly divided into three identical single large driven teeth through stamping equipment, a traditional small tooth is divided into three single small driving teeth, and the unique multi-stamping-tooth riveting forming technology can meet the set working condition requirement and also can be used for manufacturing the large driven teeth and the small driving teeth. The obvious technical advantages are also shown.

The invention, which belongs to the technical field of the AC excitation generator motor, discloses a modularized magnetic field reinforced rotor structure of an AC excitation motor, comprising asymmetric small tooth modules, symmetric small tooth modules, rotor large tooth modules, slot wedges, a rotor yoke part, an inner-layer split concentrated winding and an outer-layer magnetic field reinforced winding. The rotor yoke part is provided with rotor large-tooth modules along the circumferential direction, and an inner-layer split concentrated winding is arranged between the adjacent large-tooth modules; one sides, without tooth tips, of the asymmetric small tooth modules are connected with the slot wedges, and the symmetric small tooth modules are alternately connected with the slot wedges and then are connected with the other asymmetric small tooth module, so that a small tooth-slot wedge combined module is formed; the small tooth-slot wedge combination modules surround the outer side of the rotor yoke part, and the outer layer magnetic field strengthening windings are arranged between the adjacent small tooth-slot wedge combination modules. The motor slot current density is lower through rotor transformation, the pole slot matching is more flexible in selection, the design of low slot current and high air gap magnetic flux density of the motor is realized, and the operation reliability of the large motor is improved.

A multifunctional manicure polishing head and a production method therefor. The multifunctional manicure polishing head comprises a cutter head (1) and a handle (2); a plurality of first spiral grooves (3) are spaced in the circumferential sidewall of the cutter head (1); the cutter head (1) is provided with a tooth strip (4) formed between every two adjacent first spiral grooves (3); a plurality of large tooth segments (5) are formed in the radial section of the cutter head (1) along the circumferential direction of the cutter head (1); each large tooth segment (5) consists of a plurality of tooth strips (4); the arrangement density of the tooth strips (4) in one large tooth segment (5) varies along the circumferential direction of the cutter head (1), i.e., the tooth strips (4) in one large tooth segment (5) are arranged from sparse to dense or from dense to sparse or in an alternating sparse-and-dense pattern. The production method for the multifunctional manicure polishing head comprises the following machining steps: S1, machining a cutter head (1) and a handle (2); S2, forming a plurality of first spiral grooves (3); and S3, forming a plurality of second spiral grooves (6).

An arc-shaped oscillating saw blade with large and small teeth and an oscillating saw are provided. The arc-shaped oscillating saw blade with large and small teeth includes a connecting part and a cutting part. Sawteeth of the cutting part are arranged in an arc shape, and a plurality of adjacent sawteeth form a sawtooth unit, and each sawtooth unit includes a plurality of large teeth and a plurality of small teeth, thus forming a structure with the large and small teeth interleaved. With structural design of the saw blade with interleaved large and small teeth, an effective cutting area of the saw blade can be increased. With design of incremented angles, the sawteeth distributed in the arc shape can be formed, which facilitates reducing of the impact and vibration in the cutting process and further improves the cutting accuracy.

1. Name of the Design Product: Comb (Elliptical Integrated Large Tooth Neptune Comb). 2. Use of the Design Product: The design product is used as a comb. 3. Design Key Points of the Design Product: Lies in the shape. 4. Picture or Photograph that Best Illustrates the Design Key Points: 3D View of Design 1. 5. Design 1 is designated as the basic design.

The application discloses a tensioner assembly automatic assembly system, which comprises a shell assembly work station, a large tooth frame assembly work station, a guide block assembly work station, a small tooth frame assembly work station, a spring assembly work station and an assembly work station. The large tooth frame assembly work station is suitable for assembling a large tooth frame into an inner groove of a shell to form a shell assembly. The small tooth frame assembly work station and the spring assembly work station are suitable for assembling the small tooth frame into an inner groove of the guide block and assembling the spring into an outer wall of the guide block to form a guide block assembly. The assembly work station is suitable for assembling the shell assembly and the guide block assembly to form a tensioner assembly. The oiling process of the outer wall of the guide block is arranged behind the spring assembly work station, so that the oil loss is reduced, and the oil stain problem in the system is reduced. When the oiling is performed, the spring can be compressed, the outer wall of the guide block is exposed when the spring is deformed, and thus the oiling can be directly performed.

The present application discloses a material for a bucket tooth seat and a preparation method thereof, including the following components by weight percentage: the content of carbon is 0.15% - 0.25%, the content of silicon is 0.80% - 1.50%, the content of manganese is 0.60% - 1.20%, the content of chromium is 0.70% - 1.20%, the content of aluminum is 0.01% - 0.04%, the content of phosphorus is less than 0.035%, the content of sulfur is less than 0.035%, the content of boron is 0.001% - 0.006%, the content of yttrium is 0.02% - 0.18%, and the content of strontium is 0.01% - 0.03%, with the balance being iron and impurities; the preparation method includes a feeding process, a component adjustment process, a heating and stirring process, and a heat treatment process. The material for the bucket tooth seat of the present invention has good low-temperature mechanical properties and wear resistance at low temperatures, is widely applicable to various application ranges, and further reduces production costs. The preparation method of the present invention has a wide application range, can be used to prepare large tooth seat materials with a relatively large single weight, and also has good application potential.

The utility model discloses a thin film switch key sheet punching device which comprises a main body unit which comprises a lower platform and a base plate located over the lower platform. The horizontal fine adjustment unit comprises a plurality of wedge-shaped blocks transversely and slidably connected with the upper side wall of the lower platform and a plurality of fixing lugs fixedly installed on the upper side wall of the lower platform, the fixing lugs are in threaded connection with corresponding screw rods, and each screw rod penetrates through the corresponding fixing lug to be rotationally connected with the corresponding wedge-shaped block; a small tooth column is rotationally connected to the side, away from the wedge-shaped block, of the fixing lug, a large tooth disc meshed with the small tooth column is fixedly connected to the end, away from the wedge-shaped block, of the threaded rod, and a top block abuts against the corner of the lower side wall of the base plate. According to the utility model, the cutter does not need to be replaced when the cutter is abraded, so that the time delayed by shutdown is saved, the production cost of membrane switch punching is reduced, and the punching efficiency of the punching equipment on the membrane switch key sheet is improved.

The utility model discloses an efficient gangue loading device for underground mining, which belongs to the technical field of mine production and comprises a gangue loading vehicle, a casing box is fixedly mounted at the middle end of the bottom of the gangue loading vehicle, a through groove is formed in the middle end of the bottom of the casing box, a small toothed plate is arranged in the through groove in a sliding manner, a guide rail is arranged at the bottom of the gangue loading vehicle, and the guide rail is connected with the casing box. A large toothed plate is arranged in the middle of the guide rail, the large toothed plate and a small toothed plate are arranged in a staggered mode, a sliding groove is formed in the pouring jacket, a through groove is communicated with the interior of the sliding groove, and a connecting plate is arranged in the sliding groove in a sliding mode. The small toothed plate is driven by the connecting plate to transversely move, so that the small toothed plate can be in meshed connection with the large toothed plate, the gangue loading vehicle is positioned, continuous operation of coal miners is not needed in the gangue loading process, stability of the small toothed plate is guaranteed, and safety is greatly improved.

The utility model provides a big gear interval cutting saw blade, this big gear interval cutting saw blade includes saw handle, be provided with a plurality of saw tooth on the saw handle, the interval between saw tooth is bigger than the width of saw tooth, be provided with trapezoidal protection spare between saw tooth, the side surface of trapezoidal protection spare is in line with the side surface of saw tooth. The utility model provides big gear interval cutting saw blade, the interval between saw tooth is bigger, therefore set up trapezoidal protection spare between saw tooth, the side surface of trapezoidal protection spare is in line with saw tooth, from the side surface holds saw tooth, thereby when saw tooth carries out cutting operation, provided the protection effect of side surface, reduced the possibility of saw tooth fracture, thereby improved the service life of saw blade.

The utility model provides an accessory type agricultural film removing rake. The accessory type agricultural film removing rake comprises a base plate. Teeth are arranged at the bottom of the base plate, a baffle is detachably inserted and fixed in the middle of the base plate, and a rod body is connected and fixed to the baffle; and the teeth at the bottom of the substrate at least comprise three teeth with different lengths or diameters. Based on the arrangement of various teeth and the accessory type detachable structure, different combinations of various teeth can be effectively replaced according to different requirements, the advantages of large teeth and small teeth are effectively integrated, the problem that the large teeth cannot be cleaned up is solved, the problem that the small teeth are prone to winding is solved, and the service life of the gear is prolonged. The labor cost is greatly reduced, and the operation efficiency of agricultural film removal in small-scale planting is greatly improved.

The utility model relates to a welding tool clamp, which belongs to the technical field of welding and comprises a workpiece, a tool plate, a left large tooth piece positioning component, a right large tooth piece positioning component, a left small tooth piece pressing cylinder component, a right small tooth piece pressing cylinder component, a small tooth piece positioning component, a left pressing rod cylinder component and a right pressing rod cylinder component. According to the welding tool clamp, a left large tooth piece positioning assembly is moved leftwards by operating a first hand rotating valve, a workpiece is placed in, the angle of a large tooth piece is positioned by adjusting a conical spring pin, a small tooth piece is directly placed on a small iron block meshed with the small tooth piece, then the first hand rotating valve is operated to abut against a long rod of the workpiece, and a second hand rotating valve is operated to press the long rod; and after welding is completed, the first hand rotating valve is operated to move the large tooth piece positioning assembly on the left side leftwards, a workpiece is taken out, the whole process is convenient to operate, the working efficiency is greatly improved, meanwhile, the positioning part can be adjusted at any time in the using process, and the percent of pass of the workpiece and the durability of the tool are guaranteed.

The application discloses a light probe measurement method for a micro gear. The method is based on a light probe measuring head of a point self-focusing principle. Firstly, a standard ball is used to determine the maximum allowable measurement inclination angle of the light probe measuring head, then the offset distance required for measuring different modulus gears is determined, the measurement path is planned, and then the acquisition of the full tooth surface data of the micro gear is realized. The application adopts a 632.8nm wavelength laser, is equipped with a 100 times microscopic objective lens, and can adjust a laser spot with a spot diameter less than 1um. The application can be used for measuring the gear slot of a micro gear with a modulus less than 0.1mm. The measurement path adopted by the application can effectively reduce the measurement error introduced by the too large tooth surface inclination angle, and improves the measurement precision of the gear measurement. The method has wide application, and is especially suitable for the full tooth surface measurement of the micro gear.

The utility model provides a novel noise reduction fluted disc assembly which comprises a crank, a small tooth piece and a large tooth piece, one end of the crank is provided with a hole used for being connected with a middle shaft, the end face of one end of the crank is provided with a plurality of crank claws in the circumferential direction, and each crank claw is provided with a first installation hole. A plurality of second mounting holes are formed in the end face of one end of the crank and located on the peripheral sides of the multiple crank claws, the small tooth pieces are fixed to the multiple crank claws through the multiple fasteners, and the large tooth pieces are fixed to the end face of one end of the crank through the noise reduction assembly. According to the utility model, the large tooth sheet is fixed on the crank through the noise reduction assembly, so that when speed change is carried out, that is, the chain moves from the small tooth sheet to the large tooth sheet or from the large tooth sheet to the small tooth sheet, the chain is rubbed with the inclined surface of the noise reduction piece, and the noise reduction piece is made of engineering plastic materials, so that the noise reduction piece is not damaged. Therefore, the noise caused by friction can be avoided, the riding experience of a rider is improved, and the practical effect of the automobile seat cushion is guaranteed.

This application relates to the field of nail art tools and discloses a multi-functional nail art polishing head and a manufacturing method thereof, including a bit and a shank. The bit has a circumferential sidewall with a plurality of first spiral grooves formed at intervals, and a rack formed between each pair of adjacent first spiral grooves. A radial cross-section of the bit defines a plurality of groups of large tooth segments, each consisting of a plurality of racks, along the circumferential direction of the bit. Within each group of large tooth segments, the arrangement density of the racks varies from sparse to dense, from dense to sparse, or alternates between dense and sparse along the circumferential direction of the bit. A manufacturing method for a multi-functional nail art polishing head is also disclosed, including steps S1 of machining the bit and the shank, S2 of forming a plurality of first spiral grooves, and S3 of forming a plurality of second spiral grooves. By using blades with different arrangement densities for grinding, rough grinding and fine grinding can be performed simultaneously with the bit, eliminating the need to continually replace the nail art polishing head and making it easier for users to remove nail art accessories with different hardnesses.

A hole saw is provided that has a variety of different tooth inlays and / or sizes that protrude from the sidewall. In some embodiments, large teeth protrude from the inner diameter of the sidewall to create a cut that is greater than the thickness of the sidewall. Similarly, the tooth inlay or variation in the circumferential direction of the teeth increases the cut in the workpiece either inwardly or outwardly. In a number of different embodiments, one or both of the increased tooth protrusion and / or the tooth inlay increases the cut of the hole saw relative to the sidewall thickness. This results in improved wear resistance, reduced heat on the teeth during cutting, and facilitates waste removal.