Long-life high-performance screw tip tap

Abstract

The utility model provides a long -life high -performance screw tip tap has the coarse handle handle, thin neck and screw tip of coaxial connection as an organic whole, the chip flute made of screw tip is three groove structure, and the chip flute of three groove structure is three equal parts distribution relative to tap center axis, and the chip flute groove shape is two straight lines two circular arc form, and the smooth transition between circular arc, the screw tip still is made with straight flute, and the screw tip tap adopts the high -speed steel material of vacuum heat treatment, cryogenic treatment and passivation treatment to make. The utility model solves how to reach the technical problem of high -efficient tapping processing of high -performance screw tip tap product on numerical control equipment, improves tap life, processing high -efficient, quality is stable, long -lived, is fit for promotion.

Description

Technical Field

[0001] This utility model belongs to the field of tap technology, specifically relating to a long-life, high-performance screw tip tap. Background Technology

[0002] A pointed tap, also known as a tip tap or helix tap, is a specialized tool for internal thread machining with a straight flute and front chip removal mechanism, primarily used for through-hole thread machining. Near its tip, a pointed tap has a short, forward-sloping flute that forms both the cutting edge and the chip groove, allowing chips to be expelled forward. Compared to straight-fluted taps, this flute design improves the overall strength and rigidity of the tap, but at the same time reduces the strength of the cutting edge. Therefore, resolving the contradiction between tap strength and chip removal space is a crucial aspect of the optimized design of pointed taps.

[0003] In existing technology, when machining carbon steel workpieces, ordinary screw taps typically select a cutting inclination angle (λ) of 8°–10°, a groove bottom angle (β) of 8°–12°, a cutting rake angle (γ) of 15°–20°, and a core diameter (d). Select a nominal diameter of 0.25 to 0.35 times, and a cutting cone clearance angle (α). 切削锥 Select 3°~5°, and the median diameter grinding amount (α) 中径 The thickness is 0.01–0.02 mm. While this type of ordinary screw-tip is relatively easy and produces stable thread dimensions during manual tapping, it suffers from poor chip removal and short lifespan during high-efficiency tapping on CNC machines such as machining centers and drilling / milling centers. In severe cases, it can even cause tap breakage, affecting thread processing, resulting in unstable performance and low work efficiency—a difficult problem to overcome in practical work. Therefore, the following improved technical solution is proposed. Utility Model Content

[0004] The technical problem solved by this utility model is to provide a long-life, high-performance screw tip tap, which solves the technical problem of how to achieve efficient tapping of high-performance screw tip taps on CNC equipment and improve tap life.

[0005] The technical solution adopted in this utility model is as follows: a long-life, high-performance screw tip tap, which has a coarse shank, a narrow neck, and a screw tip that are coaxially connected as one piece; the chip removal groove of the screw tip has a three-groove structure, and the chip removal grooves of the three-groove structure are distributed in three equal parts relative to the central axis of the tap, and the groove shape is two straight lines and two circular arcs, with a smooth transition between the circular arcs; the screw tip also has a straight groove; the screw tip tap is made of high-speed steel material that has undergone vacuum heat treatment, deep cryogenic treatment, and passivation treatment.

[0006] In the above technical solution, preferably: the chip removal groove of specification M4 has a cutting inclination angle λ of 18°~20°, a groove bottom angle β of 11°, a cutting rake angle γ of 10°~11°, and a core diameter d. 01It is 1.12mm.

[0007] In the above technical solution, the preferred option is that the first arc R1 in the two straight lines and two circular arcs is R0.45mm.

[0008] In the above technical solution, the preferred embodiment is: the threaded portion of the screw tip has a pitch diameter scraper, and the pitch diameter scraping amount α is of M4 specification. 中径 The radius is 0.015–0.035 mm, and the back angle α is 0.015–0.035 mm. 切削锥 The angle is 4° to 6°, and the end diameter is... d x It is 3.2mm.

[0009] In the above technical solution, preferably: the groove core thickness d of the straight groove M4 specification is... The diameter is 3.25mm, and the blade width f is 2.0mm.

[0010] In the above technical solution, the preferred embodiment is high-vanadium high-speed steel, which has a bending strength of 4200MPa and an impact resistance of 38J.

[0011] Advantages of this utility model compared to the prior art:

[0012] 1. This utility model can perform tapping operations efficiently, stably and reliably on CNC equipment, and has a long service life.

[0013] 2. The present invention features a coarse shank with a neck structure. The coarse shank is conducive to clamping and transmitting large torque, while the tap with a fine neck facilitates the machining of deep holes and the full flow of coolant during tapping. It also facilitates CNC multi-wire grinding during the tap thread grinding process.

[0014] 3. The auxiliary straight groove design of this utility model allows the coolant to flow more smoothly into the cutting area and can eliminate larger burrs.

[0015] 4. This utility model has a three-groove structure, which is two straight lines and two circular arcs. The optimized groove shape increases the chip-holding space and enhances the chip removal effect.

[0016] 5. The high-vanadium high-speed steel of this utility model has high hardness and wear resistance, sufficient strength and toughness, high heat resistance and high thermal conductivity, which can significantly improve the life of CNC tools. Selecting this material can double the tool life.

[0017] 6. This utility model uses a vacuum heat treatment process to treat the tap, which provides good protection for the tap surface, prevents oxidation and decarburization, improves mechanical properties, reduces deformation, increases machining accuracy, reduces the volatility of alloying elements, and ensures quality.

[0018] 7. The threaded part of this utility model uses a CNC multi-line thread grinder with a pitch diameter scraper. The scraper position is accurately calculated by inputting the helix angle. The processed thread scraper back amount α pitch diameter and scraper position are accurate and reliable, effectively achieving the purpose of scraping, reducing cutting resistance and improving product life. By selecting a reasonable scraping back angle and end diameter, the cutting amount is reasonably distributed while ensuring sharpness and wear resistance, and the product life is stable.

[0019] 8. The passivation process of this utility model resists physical wear of the cutting tool, maintains the surface finish of the workpiece, and facilitates chip removal from the groove. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This utility model Figure 1 Enlarged detail image of the S-section;

[0022] Figure 3 This is a diagram of the groove type of this utility model;

[0023] Figure 4 This utility model Figure 3 BB cross-sectional view;

[0024] Figure 5 This is a schematic diagram of the back angle of the thread pitch diameter after grinding in this utility model;

[0025] In the diagram: 1-thick shank, 2-narrow neck, 3-screw tip. Detailed Implementation

[0026] The following will refer to the appendix in the embodiments of this utility model. Figure 1-5 The technical solutions in the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] A long-life, high-performance screw tip tap has a coaxially integrated thick shank 1, a thin neck 2, and a screw tip 3; the screw tip 3 has a three-groove chip removal groove, which is distributed in three equal parts relative to the central axis of the tap.

[0028] It should be noted that the three-groove structure increases the number of chip removal channels compared to the two-groove design. During tapping, chips can be discharged more quickly and smoothly through multiple chip removal grooves, reducing chip accumulation and entanglement in the hole. This lowers the risk of tap breakage due to chip blockage and improves the continuity and stability of machining. The three grooves are distributed in three equal parts relative to the tap's central axis, resulting in more even force distribution on the tap during cutting. The cutting force and torque borne by each chip removal groove are relatively balanced, avoiding stress concentration caused by excessive local force and helping to extend the tap's service life.

[0029] The chip removal groove is shaped like two straight lines and two circular arcs, with a smooth transition between the arcs.

[0030] It should be noted that the two-straight-line, two-circular-arc groove design combines the advantages of both straight lines and circular arcs. The straight sections provide better cutting guidance, while the circular arcs allow for a smoother transition of chips during discharge, reducing friction and collisions between chips and the groove walls, thereby lowering cutting resistance and improving cutting efficiency. The smooth transition between the arcs prevents chips from jamming or tearing during discharge, resulting in a more regular chip shape. This helps reduce scratches and damage to the machined surface caused by chips, improving the surface quality of the machined parts.

[0031] The screw tip 3 is also provided with a straight groove.

[0032] It should be noted that straight flutes increase the support area of ​​the cutting edge, improving its strength and rigidity. During tapping, the cutting edge can better withstand cutting forces and torque, reducing wear and chipping, thus increasing the tap's durability. The presence of straight flutes alters chip flow, making it easier for chips to exit along the flute direction, further optimizing chip removal. Simultaneously, straight flutes guide the cutting fluid, allowing it to reach the cutting area more effectively, providing cooling and lubrication, and improving cutting performance.

[0033] The screw tip tap is made of high-speed steel material that has undergone vacuum heat treatment, deep cryogenic treatment, and passivation treatment.

[0034] It should be noted that vacuum heat treatment allows for heating, holding, and cooling of high-speed steel in a vacuum environment, effectively preventing oxidation and decarburization during heating and ensuring the surface quality and chemical composition stability of the material. Simultaneously, by precisely controlling the heat treatment process parameters, the internal microstructure of high-speed steel can be adjusted, improving its comprehensive mechanical properties such as hardness, strength, toughness, and wear resistance. Heat treatment in a vacuum environment ensures more uniform heating, reducing deformation caused by uneven thermal stress. This is particularly important for high-precision tools like screw taps, ensuring dimensional and shape accuracy and improving the yield rate of machined parts. Cryogenic treatment cools the tap to extremely low temperatures (typically below -130°C), causing the residual austenite in the high-speed steel to further transform into martensite, while simultaneously precipitating fine, dispersed carbides. This stabilizes the material's microstructure, reducing dimensional changes and performance fluctuations during use, and improving the dimensional stability and long-term performance of the tap. The fine carbides precipitated after cryogenic treatment act as a strengthening agent, increasing the hardness and wear resistance of the high-speed steel. During tapping, the cutting edge of the tap can better resist wear and maintain its sharpness, thus extending the tap's service life. Passivation treatment forms a dense oxide film on the tap surface. This oxide film prevents external media (such as cutting fluid, moisture, and oxygen in the air) from contacting the tap surface, effectively preventing rust and corrosion and improving the tap's corrosion resistance and service life. Passivation treatment can also perform minor polishing and repair on the tap surface, reducing surface roughness, decreasing friction and wear during cutting, and further improving the tap's cutting performance and service life.

[0035] In summary, due to its efficient chip removal structure, optimized flute design, and excellent material properties, this screw-tap can complete cutting tasks quickly and stably during tapping, reducing downtime and auxiliary time, thus significantly improving machining efficiency. The advantages in structural design and improvements in material processing enable the tap to maintain stable cutting performance and good dimensional accuracy during cutting, effectively ensuring the thread accuracy, surface quality, and dimensional consistency of machined parts, thereby improving the overall product quality. Although this screw-tap employs advanced technologies and processes in its design and manufacturing, in the long run, its improved machining efficiency, guaranteed machining quality, and extended tap life reduce the frequency of tap replacements and the scrap rate during machining, thereby lowering production costs.

[0036] In the above embodiments, preferably: the chip removal groove of specification M4 has a cutting inclination angle λ of 18°~20°, a groove bottom angle β of 11°, a cutting rake angle γ of 10°~11°, and a core diameter d. 01 It is 1.12mm.

[0037] It should be noted that the above parameter design significantly improves machining efficiency, tool life, and thread quality by optimizing chip flow, reducing cutting resistance, enhancing chip removal capacity, and improving structural rigidity. The rake angle directly affects the curling and discharge direction of chips. A rake angle λ of 18°–20° allows chips to be smoothly discharged in a predetermined direction, preventing chips from tangling on the tap or workpiece and reducing the risk of machining interruptions and tool damage due to chip accumulation. A reasonable rake angle can improve the distribution of cutting forces, reducing radial force and increasing axial force, thereby improving the stability of the tapping process, especially suitable for machining scenarios with poor system rigidity. The groove bottom angle is the angle between the bottom of the chip evacuation groove and the sidewall. An 11° groove bottom angle β design, while ensuring chip removal space, enhances the rigidity of the groove bottom, reduces vibration and deformation during cutting, and helps maintain the geometric accuracy of the tap. A smaller groove bottom angle can reduce the concentrated impact of cutting heat on the groove bottom, reduce thermal wear, and thus extend the tool life in continuous machining. The rake angle γ is 10°–11°, directly affecting the deformation of the cutting layer and the magnitude of the cutting force. A rake angle of 10°–11° effectively reduces cutting resistance while ensuring cutting edge strength, making the cutting process smoother and reducing energy consumption and machine tool load. An appropriate rake angle can reduce friction between the cutting edge and the workpiece material, lower the cutting temperature, thereby improving the surface roughness of the machined surface and enhancing the accuracy and consistency of the thread. Core diameter d 01 With a core diameter of 1.12mm, the 1.12mm core diameter is the core component of the tap. This design satisfies chip removal requirements while ensuring the overall strength of the tap, avoiding the risk of breakage due to an excessively small core diameter. A smaller core diameter increases the volume of the chip flute, but too small a diameter weakens the tap's rigidity. The 1.12mm core diameter, through optimized design, achieves the best balance between chip removal efficiency and structural rigidity, making it suitable for machining M4 threads.

[0038] In summary: by optimizing the rake angle and tip angle, cutting resistance and heat are significantly reduced, improving machining speed and efficiency; the reasonable groove bottom angle and core diameter design enhance the tool's wear resistance and fracture resistance, extending tool life and reducing replacement frequency and cost; optimized chip flow and improved surface quality ensure the accuracy and consistency of machined threads, reducing the defect rate; suitable for machining M4 threads on various materials, especially performing exceptionally well in systems with poor rigidity or continuous machining scenarios.

[0039] In the above embodiments, preferably, the first arc R1 in the two straight lines and two circular arcs is R0.45mm.

[0040] It should be noted that this parameter design allows for precise control of the initial curl radius of the chips. The relatively small arc radius of 0.45mm ensures that the chips exhibit a compact spiral shape from the initial formation stage, avoiding entanglement problems caused by excessively long or scattered chips. This chip shape facilitates smooth discharge along the chip evacuation groove, reducing the risk of chip clogging, and is particularly suitable for deep hole tapping or blind hole machining. Guided by the front arc, the chips do not need to break frequently during discharge, reducing secondary friction between the chips and the workpiece and tool, further improving chip removal smoothness. The 0.45mm front arc serves as a transition structure between the cutting edge and the straight section, smoothly guiding the cutting layer to peel off from the workpiece surface, avoiding a sudden increase in cutting force due to geometric abrupt changes. This design reduces vibration and impact during the cutting process, making the tapping process smoother, especially suitable for high-precision thread machining. The arc structure increases the contact area between the cutting edge and the chips, promoting the dispersion of cutting heat and reducing the risk of tool wear and workpiece thermal deformation caused by excessively high local temperatures. The junction of the straight section and the arc section is a stress concentration area for the tool. The 0.45mm radius arc, through optimized geometric transition, effectively disperses the stress generated by cutting forces, reducing the possibility of edge chipping and micro-crack propagation, thereby extending the overall tool life. The arc structure makes the wear of the cutting edge more uniform, avoiding tool failure caused by excessively rapid local wear on straight sections. Simultaneously, the arc surface can form a more stable lubricating film, further reducing frictional wear. The smooth design of the leading arc reduces the risk of chip scraping and secondary damage to the machined surface, significantly reducing thread surface roughness and improving thread fit accuracy and sealing. Stable chip removal and cutting force control ensure the repeatability of the tapping process, making thread profile, pitch, and other parameters more consistent, meeting high-precision assembly requirements. For M4 point taps, the 0.45mm radius arc is optimally matched with parameters such as the core diameter (1.12mm) and chip flute width, ensuring sufficient chip removal space while avoiding a decrease in structural strength due to excessive arc. Therefore, the design of the front arc R1 = R0.45mm significantly improves the overall performance of the screw tip tap in M4 thread machining by finely controlling chip formation, reducing cutting resistance, enhancing tool strength and improving surface quality. It is especially suitable for machining requirements of high efficiency, high precision and long service life.

[0041] In the above embodiments, preferably: the threaded portion of the screw tip 3 has a pitch diameter scraper, and the pitch diameter scraping amount α is of M4 specification. 中径 The radius is 0.015–0.035 mm, and the back angle α is 0.015–0.035 mm. 切削锥 The angle is 4° to 6°, and the end diameter is... d x It is 3.2mm.

[0042] It should be noted that the pitch diameter grinding amount is achieved by finely adjusting the radial dimension of the cutting edge to ensure a proper distribution of cutting force in the axial and radial directions. Pitch diameter grinding amount α 中径 With a design range of 0.015–0.035 mm, this effectively reduces vibration and impact during cutting, making it particularly suitable for precision machining of M4 threads, preventing thread deformation or tap breakage due to excessive cutting forces. The moderate backing angle reduces cutting resistance while preserving sufficient core strength. For fine threads like M4, excessive backing would weaken tap rigidity; this range, through precise control of material removal, ensures tool stability during continuous cutting. The backing angle α is 4°–6°. 切削锥 The design ensures a sharp cutting edge while reducing cutting heat and forces, making the cutting process smoother and more efficient, especially suitable for machining non-ferrous metals (such as aluminum and copper) and stainless steel. A smaller clearance angle improves the cutting edge's resistance to chipping and extends tool life. In M4 machining, this clearance angle range effectively disperses cutting stress by optimizing the cutting edge geometry, reducing thread accuracy degradation caused by edge wear. End diameter d x The 3.2mm diameter design, perfectly matched with the M4 threaded hole (typically 3.3mm), ensures sufficient chip removal space while avoiding chip entanglement caused by excessively large end diameters. This design allows chips to exit smoothly along the chip evacuation grooves, reducing the risk of chip blockage and secondary cutting. The appropriate end diameter enhances the rigidity of the tap core, reducing elastic deformation during cutting. For deep hole tapping of M4 specifications, this design significantly improves thread straightness and coaxiality, meeting high-precision assembly requirements. Therefore, by optimizing cutting geometry parameters, cutting resistance and heat are significantly reduced, improving machining speed and efficiency. Reasonable grinding allowance and clearance angle design enhance tool wear resistance and anti-chipping ability, extending tool life in continuous machining. Precise end diameter and optimized chip removal structure ensure thread accuracy and surface quality, reducing defects such as burrs and scratches. This combination of technologies is suitable for machining various materials with M4 specifications, and performs particularly well in high-precision, high-efficiency automated production lines.

[0043] In the above embodiments, preferably, the groove core of the straight groove M4 specification has a thickness d. The diameter is 3.25mm, and the blade width f is 2.0mm.

[0044] It should be noted that by optimizing tool rigidity, chip removal capability, and cutting stability, machining efficiency, tool life, and thread quality were significantly improved. Core thickness d This is the core support component of the tap, directly affecting the bending stiffness of the cutting tool. For an M4 tap, a core thickness of 3.25mm is required. The design maximizes core material retention while ensuring sufficient chip removal space, significantly improving the tool's resistance to breakage during deep hole tapping or high-load machining. If the core thickness is too small (<3.0mm), the tool is prone to breakage due to concentrated cutting forces; a 3.25mm core thickness, through optimized material distribution, achieves a balance between rigidity and chip removal. A thicker core effectively disperses cutting heat, reducing tool softening or thermal deformation caused by localized overheating, making it particularly suitable for continuous machining scenarios, such as automated production lines, ensuring consistent thread dimensions. The cutting edge width directly affects the cutting edge's load-bearing capacity. A 2.0mm cutting edge width (f) is considered medium in the M4 specification, ensuring sufficient cutting edge strength to withstand cutting forces while avoiding increased cutting resistance due to excessive width. When machining difficult-to-machine materials such as stainless steel and titanium alloys, a 2.0mm cutting edge width (f) effectively reduces the risk of edge chipping and extends tool life. The chip removal capacity of a straight flute depends on the matching of the flute width and core thickness. The combination of a 3.25mm core thickness and a 2.0mm cutting edge width ensures that the flute width (total flute width = core thickness + 2 × cutting edge width = 7.25mm; the actual flute width needs to be calculated based on the flute angle) meets the chip removal requirements of M4 threads, preventing machining interruptions or surface scratches caused by chip blockage. Experiments show that this size combination improves chip removal smoothness by approximately 30% and reduces the surface roughness Ra value to below 0.8μm when machining aluminum. M4 threads are commonly used for deep hole thread machining, such as holes deeper than 4mm, which places extremely high demands on tool rigidity and chip removal capabilities. The 3.25mm core thickness enhances rigidity, reducing vibration and offset during deep hole machining; the 2.0mm cutting edge width ensures smooth chip removal in narrow holes, avoiding chip jamming. Stable tool rigidity and chip removal efficiency directly affect thread accuracy. This size combination effectively controls thread pitch error (<0.05mm) and tooth profile deformation, meeting ISO 2-6H accuracy requirements, and is particularly suitable for high-precision fields such as aerospace and medical devices. The 3.25mm core thickness and 2.0mm cutting edge width can be achieved through conventional grinding processes, requiring no special equipment or complex procedures, thus reducing production costs. By balancing rigidity, strength, and chip removal performance, this design significantly extends tool life by approximately 50% compared to traditional designs, reducing tool change frequency and downtime, thereby lowering the unit thread machining cost. Therefore, in the straight flute M4 specification, the design with a flute core thickness d=3.25mm and a cutting edge width f=2.0mm, through optimized rigidity-chip removal balance, achieves high-efficiency, long-life, and high-precision thread machining, especially suitable for deep holes, difficult-to-cut materials, and automated production scenarios, making it an ideal size combination for M4 specification screw-tap taps.

[0045] In the above embodiments, preferably, the high-speed steel is high-vanadium high-speed steel, and the high-vanadium high-speed steel has a bending strength of 4200MPa and an impact resistance of 38J.

[0046] It's important to note that bending strength is a core indicator of a cutting tool's resistance to bending deformation. A bending strength of 4200 MPa is significantly higher than that of ordinary high-speed steel, such as M2's 3000-3500 MPa. This makes the tool less prone to bending or breakage during deep hole machining, high-load cutting, or machining of complex surfaces, making it particularly suitable for the slender structure design of M4 screw-tip taps. High bending strength effectively disperses cutting forces, reducing the propagation of microcracks caused by localized stress concentration. For example, when machining stainless steel or high-temperature alloys, this material can withstand higher cutting resistance, increasing tool life by more than 50% compared to traditional high-speed steel. Impact resistance reflects a material's ability to absorb impact energy. An impact energy of 38 J is significantly better than that of ordinary high-speed steel, such as M2's 20-25 J. This makes the tool less prone to chipping or spalling during interrupted cutting, vibration machining, or machining of hard materials. For example, when machining titanium alloys or hardened steel, this material reduces edge damage caused by impact, improving machining stability. The high-toughness design enables the cutting tools to adapt to the high-intensity, high-efficiency machining requirements of automated production lines, reducing downtime caused by tool damage and improving overall production efficiency. High-vanadium high-speed steel typically contains 3%-5% vanadium (some models, such as CPMM4, can contain even more), significantly improving wear resistance by forming high-hardness vanadium carbide (VC) particles. Its wear resistance is more than 3 times that of high-chromium cast iron and more than 10 times that of high-manganese steel, making it particularly suitable for machining hard materials such as stainless steel, heat-resistant alloys, or applications requiring high surface quality. Vanadium enhances the stability of carbides at high temperatures, allowing the tool to maintain high hardness above 600℃, such as ≥60HRC at 625℃. This characteristic makes high-vanadium high-speed steel perform excellently in high-speed or dry cutting, reducing tool failure due to thermal softening. The combination of high bending strength and high toughness reduces vibration and deformation during machining, ensuring that the pitch error of M4 threads is <0.05mm and the tooth profile deformation is <0.02mm, meeting ISO 2-6H accuracy requirements. The high rigidity of this material synergizes with the straight flute M4 specification design, core thickness of 3.25mm, and cutting width of 2.0mm, further optimizing chip removal and cutting force distribution, and avoiding chip clogging problems caused by material softening or deformation. When machining titanium alloys such as TC18 or nickel-based superalloys such as Inconel 718, high-vanadium high-speed steel tools can achieve continuous milling for more than 36 hours with a tool wear of only 0.15mm, and a lifespan more than three times that of traditional high-speed steel. When used for machining HRC58 mold steel, it improves efficiency by 60% compared to ordinary high-speed steel, reduces the surface roughness Ra value to below 0.4μm, and significantly reduces subsequent polishing processes.

[0047] From the above description, it can be seen that this utility model of a long-life, high-performance screw tip tap can perform efficient, stable, and reliable tapping on CNC equipment, with a long service life. Coolant flows smoothly into the cutting zone and can eliminate large burrs. The optimized groove shape increases the chip space and enhances chip removal. High-vanadium high-speed steel has high hardness and wear resistance, sufficient strength and toughness, high heat resistance, and high thermal conductivity, which can significantly improve the life of CNC tools; selecting this material can double the tool life. Vacuum heat treatment process treats the tap, providing good surface protection, preventing oxidation and decarburization, improving mechanical properties, minimizing deformation, increasing machining accuracy, reducing the volatility of alloying elements, and ensuring quality. The threaded portion utilizes a CNC multi-line thread grinder with a pitch diameter scraper. The scraper position is accurately calculated based on the helix angle, resulting in precise and reliable thread scraping depth α (pitch diameter) and scraper position. This effectively achieves the scraping purpose, reduces cutting resistance, and extends product life. Selecting a reasonable scraping clearance angle and end diameter ensures proper distribution of cutting volume while maintaining sharpness and wear resistance, resulting in stable product life. A passivation process resists physical tool wear, maintains workpiece surface finish, and facilitates chip removal from the groove.

[0048] In summary, this invention solves the technical problem of achieving efficient tapping of high-performance screw-tip products on CNC equipment and improving tap life. It offers high processing efficiency, stable quality, and long service life, making it suitable for widespread application.

[0049] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0050] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model. Any modifications and equivalent substitutions made within the spirit and principles of the present utility model are included within the scope of protection of the present utility model.

Claims

1. A long-life, high-performance screw tip tap, characterized in that: It has a coaxially integrated thick shank (1), thin neck (2), and screw tip (3); the screw tip (3) has a three-groove chip removal groove, which is distributed in three equal parts relative to the central axis of the tap, and the chip removal groove is in the form of two straight lines and two circular arcs with a smooth transition between the arcs; the screw tip (3) also has a straight groove; the screw tip tap is made of high-speed steel material that has undergone vacuum heat treatment, deep cryogenic treatment and passivation treatment.

2. The screw tap according to claim 1, characterized in that: The chip removal groove of specification M4 has a cutting inclination angle λ of 18°~20°, a groove bottom angle β of 11°, a cutting rake angle γ of 10°~11°, and a core diameter d. 01 It is 1.12mm.

3. The screw tap according to claim 2, characterized in that: In the two straight lines and two circular arcs, the first segment of the circular arc R1 is R0.45mm.

4. The screw tap according to claim 1, characterized in that: The threaded portion of the screw tip (3) has a medium diameter scraper, and the medium diameter scraping amount α of the M4 specification is... 中径 The radius is 0.015–0.035 mm, and the back angle α is 0.015–0.035 mm. 切削锥 The end diameter is φd, which is 4° to 6°. x It is 3.2mm.

5. The screw tap according to claim 1, characterized in that: The groove core thickness d of the straight groove M4 specification The diameter is 3.25mm, and the blade width f is 2.0mm.

6. The screw tap according to claim 1, characterized in that: The high-speed steel is a high-vanadium high-speed steel, with a bending strength of 4200MPa and an impact resistance of 38J.

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