Threading milling tools and their cutting elements

Abstract

The present invention relates to an indexable cutting element (1, 30, 60) for a thread milling tool, comprising first and second main surfaces (2, 3) arranged opposite to each other and facing in opposite directions, and an outer peripheral surface (4) connecting the first and second main surfaces, wherein the outer peripheral surface comprises an even number of at least four outer peripheral sub-surfaces (5, 5', 6, 6', 7, 7') arranged in pairs opposite to each other on both sides of the cutting element and facing in opposite directions. For each pair of outer peripheral sub-surfaces, one sub-surface includes one or more thread teeth (9) having a rake face (15) facing a first direction (S1), and the other sub-surface includes one or more thread teeth (9) having a non-cutting surface (18, 19, 31, 32) and / or a rake face (15) facing a second direction (S2), the second direction (S2) being opposite to the first direction (S1).

Description

Technical Field

[0001] The present invention relates to metal cutting, and more particularly, to a tool for machining threads on a metal workpiece.

Background Art

[0002] Various methods for machining threads on metal workpieces are known. One such method is thread milling, where the thread is generated using a helical interpolation tool path in which the tool moves along the axis of rotation by a distance corresponding to the thread pitch while the tool makes one revolution along the surface of the workpiece, i.e., using a circular ramp motion of the thread milling tool.

[0003] Some thread milling tools often include replaceable cutting elements or inserts made of cemented carbide. WO 2005 / 080037 discloses a slot milling cutter in which a single cutting insert is mounted in a slot in front of the tool. The cutting insert has two sets of diametrically opposed cutting teeth arranged to engage the workpiece during cutting. The cutting insert has serrations that cooperate with serrations in the slot to stabilize the positioning of the cutting insert in the radial direction of the thread milling cutter.

[0004] As with any other cutting element, the thread milling cutting element wears during cutting and ultimately needs to be replaced due to wear. For efficiency and economic reasons, it may be desirable to use the cutting element for as long as possible.

[0005] Therefore, it is necessary to extend the tool life of the cutting element for the thread milling tool.

Summary of the Invention

[0006] The object of the present invention is to mitigate the drawbacks of the prior art and to provide a cutting element for the above-described type of thread milling tool that can be used for a long period of time until replacement is necessary.

[0007] Accordingly, according to a first aspect, the present invention relates to a cutting element for a threading milling tool, comprising first and second main surfaces arranged opposite to each other and facing in opposite directions, and an outer peripheral surface connecting the first and second main surfaces. The outer peripheral surface includes an even number of outer peripheral sub-surfaces arranged in pairs on the opposite side of the cutting element and facing in opposite directions. For each pair of outer peripheral sub-surfaces, one sub-surface includes one or more threading teeth having a rake face facing a first direction, and the opposite sub-surface includes a non-cutting surface and / or one or more threading teeth having a rake face facing a second direction, the second direction being opposite to the first direction. The number of outer peripheral sub-surfaces is at least four.

[0008] This makes the cutting element indexable, meaning it can be mounted in at least two different orientations within the slot of the thread milling tool body, thereby enabling different pairs of peripheral subsurfaces depending on the orientation in which the cutting element is mounted. As a result, the tool life of the cutting element is extended. Indexable cutting elements have been known for many different types of cutting tools, but not for the type of thread milling tool described herein.

[0009] It may be preferable for both subsurfaces of each pair of outer peripheral subsurfaces to include one or more threading teeth, as this provides high productivity. However, it is also conceivable that only one of the pair of outer peripheral subsurfaces has one or more threading teeth, and the opposite subsurface has a non-cutting surface, for example, a flat surface positioned so that when the cutting element is mounted in the slot of the thread milling tool body, it does not protrude beyond the outer circumference of the tool body, or at least not to the extent of interfering with the threading process.

[0010] The first and second main surfaces may be flat or substantially flat surfaces extending in planes parallel to each other. The central neutral plane may be located between the planes on which the first and second main surfaces extend and may extend parallel to these planes. The central axis of the cutting element extends perpendicular to the central neutral plane from the first main surface to the second main surface.

[0011] The cutting element may include a through-hole extending from a first main surface to a second main surface along the central axis of the cutting element. Such a through-hole may be used to secure the cutting element within a slot of the threading milling tool body, for example, by using screws or other fastening elements.

[0012] Each threaded tooth may include a rake face, a relief face (or clearance face), and a cutting edge formed at the intersection between the rake face and the relief face.

[0013] The rake face of the threaded tooth may correspond to the plane on which the first and second principal surfaces extend, or may extend within each of the parallel planes. In other words, the first and second directions, which are opposite to each other, may be perpendicular to such planes.

[0014] In other embodiments, the rake face may not be located in a plane parallel to the plane on which the first and second principal surfaces extend, but instead may be inclined with respect to such a plane, for example, to obtain an optimal rake angle. Furthermore, each rake face may not necessarily be a flat surface, but may have a partially curved shape and may include additional geometric features such as chip grooves to improve operability, for example, smoother cutting and improved chip breaking.

[0015] Furthermore, the rake surface of the tooth may be slightly inclined circumferentially along the outer peripheral surface and toward the central plane, and it is envisioned that a small helical angle will be formed for smoother cutting.

[0016] The fact that the first and second directions are opposite to each other should be understood at least when viewing the cutting element in a side view toward the outer surface along the direction parallel to the direction in which each opposing outer peripheral subsurface extends.

[0017] The fact that the second direction is opposite to the first direction corresponds to an arrangement where the surface normals at corresponding points on the rake faces of the threading teeth on opposing peripheral surfaces, located either within the central plane or on different sides of the central plane, both point toward the central plane or away from the central plane on different sides.

[0018] The cutting element can have a positive basic shape. It is also conceivable that the cutting element has a negative shape. The cutting element can be made from wear-resistant materials such as cemented carbide.

[0019] Each pair of peripheral subsurfaces is positioned on either side of the cutting element and faces in opposite directions. When "opposite direction" is used to refer to the direction in which the peripheral subsurfaces face, it should be understood as directions that are opposite to each other when viewed in a plan view of at least the first or second main surface.

[0020] When used herein, with respect to an outer peripheral subsurface having one or more threaded teeth, the direction toward which such an outer peripheral subsurface faces should be understood as the direction toward which the surface would face in the absence of such teeth, or the direction toward which such threaded teeth protrude. When viewed in a plan view of the first or second main surface, this direction is radial with respect to the central axis of the cutting element, outward from the outer peripheral subsurface, and perpendicular to the direction toward which the threaded teeth are arranged in a line on the outer peripheral subsurface.

[0021] In some embodiments, the surface normals of any two opposite points on each of the two peripheral subsurfaces of a pair of peripheral subsurfaces (i.e., points opposite each other with respect to the central axis and central plane of the cutting element) are parallel but extend in opposite directions, i.e., the angle between such surface normals is 180°.

[0022] The peripheral subsurfaces can be adjacent to one another along the peripheral surface, in the circumferential direction around the central axis of the cutting element, for example, without any other intermediate portions of the peripheral surface located between the peripheral subsurfaces. Thus, the peripheral surface may be entirely formed by the peripheral subsurfaces, but it is also conceivable that the peripheral surface may include additional segments that are not considered part of any peripheral subsurface according to this disclosure, for example, portions of the peripheral surface that are oriented in a different direction from any of the peripheral subsurfaces.

[0023] According to some embodiments, the cutting element has six peripheral subsurfaces. Preferably, the peripheral subsurfaces are arranged symmetrically around the peripheral surface of the cutting element. A cutting element having six peripheral subsurfaces is indexable up to three times, thus not only extending tool life but also providing particularly easy access to suitable contact surfaces positioned to abut against corresponding support surfaces in the slots of the thread milling tool body, which can help stabilize the cutting element relative to the thread milling tool body. However, the cutting element may have fewer, for example, four, or more, for example, eight or ten peripheral subsurfaces, and it is conceivable that suitable contact surfaces can also be applied to such cutting elements.

[0024] According to some embodiments, each peripheral subsurface includes one or more uncut surfaces and one or more threaded teeth. The uncut surfaces may be located on one or both sides of the central neutral surface. Preferably, each peripheral subsurface has the same number of threaded teeth. According to some embodiments, each peripheral subsurface comprises two or more threaded teeth arranged in a row along the peripheral subsurface. It would be beneficial to have as many cutting teeth as possible. However, the number of cutting teeth that can be applied to the peripheral subsurface may be limited depending on the size of the cutting element and the type of thread being machined (e.g., pitch and dimensions). According to some embodiments, each peripheral subsurface has three threaded teeth.

[0025] When each peripheral secondary surface has two or more cutting teeth, a certain degree of redundancy is obtained so that the cutting element does not depend on all the cutting teeth not being damaged. For example, even if one tooth in the tooth row of the peripheral secondary surface is worn or damaged in some way, the remaining undamaged teeth in the tooth row ensure that the correct thread shape is machined on the workpiece, so the cutting element does not necessarily have to be indexed or replaced immediately. Therefore, arranging two or more threading teeth in a row on each peripheral secondary surface may increase the tool life.

[0026] According to some embodiments, the directions in which two adjacent peripheral secondary surfaces face along the outer peripheral surface differ by an angle equal to 360° divided by the total number of peripheral secondary surfaces when the first or second main surface is viewed in a plan view. Thereby, the peripheral secondary surfaces are arranged symmetrically around the central axis of the cutting element, and in the plan view of the first or second main surface, form a cutting element having a general shape of a regular polygon with a number of sides corresponding to the number of peripheral secondary surfaces. Thereby, the cutting element can be easily mounted in different orientations within the slot of the threading milling tool body.

[0027] According to some embodiments, the cutting element includes six peripheral secondary surfaces, and the rake faces of the teeth of adjacent peripheral secondary surfaces face in different directions. The different directions may be completely opposite, which corresponds to the case where each rake face extends in a plane parallel to each other. On the other hand, if the rake faces are not arranged in parallel, the directions in which each rake face faces do not have to be completely opposite. In any case, both of the respective rake faces are located on different sides of the central plane of the cutting element, and will face towards or away from the central plane.

[0028] Such a configuration may be preferable for a cutting element having six peripheral secondary surfaces, but may also be applicable to a cutting element having more peripheral secondary surfaces, such as ten. Thereby, the indexing of the cutting element with respect to the threading milling tool body It can be carried out by rotating the cutting element around its central axis by an angle corresponding to 10170 of TIFF2026511289000002.tif, where n is the number of outer peripheral flank surfaces. In other words, in the case of a cutting element having six outer peripheral flank surfaces symmetrically arranged around the central axis of the cutting element, the indexing is performed by rotating the cutting element by an angle of 120° around its central axis.

[0029] According to some embodiments, the rake face of each threading tooth includes a chip groove. The chip groove increases the rake angle (becomes more positive), can improve the control of chip formation, and may be beneficial when machining a specific workpiece material. For example, such a chip groove results in a reduction in the cutting force and a decrease in temperature, thereby improving the soundness of the surface of the machined workpiece.

[0030] According to some embodiments, the cutting element is a one-piece body. Such a one-piece body may be a body made entirely of sintered cemented carbide directly pressed and sintered to its final shape, or may be a combination of a plurality of parts inseparably bonded to each other during sintering, or may be a combination by, for example, brazing or any other suitable means for bonding a part to the one-piece body. For example, such a cutting element may be formed by two identical parts bonded to each other, each of the identical parts having at least four outer peripheral flank surfaces, each having a non-cutting surface or one or more threading teeth, and the identical parts being bonded in such a way that each of the resulting at least four outer peripheral flank surfaces includes both a non-cutting surface (from one of the identical parts) and one or more threading teeth (from the other part). Instead of being formed as a one-piece body, it is also envisaged that the cutting element is formed by two such identical parts that are fixed in the configuration as described above, rather than being mounted to each other when mounted together in a slot of a threading milling tool body.

[0031] Therefore, according to some embodiments, the cutting element includes two separate parts that are detachably arranged from each other. Apart from the simplified manufacturing process, such a cutting element may also offer other advantages. For example, the non-fixed contact surfaces between the parts allow for slight movement between them, resulting in a beneficial damping effect during machining, which can reduce vibrations, for example, and thereby improve the machining results.

[0032] According to some embodiments, the cutting element has at least two contact surfaces that are oriented in different directions and are arranged to contact the respective support surfaces in the slot of the tool body in order to prevent displacement of the cutting element relative to the tool body when the cutting element is mounted in the slot.

[0033] Preferably, the contact surfaces are arranged such that each contact surface that abuts against the corresponding support surface in the slot when the cutting element is mounted in the slot of the thread milling tool body extends obliquely with respect to the central axis of the thread milling tool body. This ensures that the two obliquely positioned contact surfaces face different directions and abut against the corresponding support surfaces in the slot of the thread milling tool body, thereby providing stable fixation of the cutting element to the tool body.

[0034] According to some embodiments, the contact surface is formed by a non-cutting surface included in the outer peripheral subsurface. This provides a convenient design for stabilizing the cutting element in the slot of the threading milling tool body, and eliminates the need for additional contact surfaces positioned in directions other than the outer peripheral subsurface. Nevertheless, according to alternative embodiments, additional contact surfaces may be formed on the outer peripheral surface that is not part of the outer peripheral subsurface.

[0035] For example, in the case of a cutting element having only four peripheral subsurfaces, i.e., a cutting element that is square or substantially square when viewed in a plan view of the first or second main surface, it may not be appropriate to use any of the non-cutting surfaces on the peripheral subsurfaces as contact surfaces, since the peripheral subsurfaces do not extend obliquely with respect to the central axis of the thread milling tool body when the cutting element is mounted in its slot. In such cases, a dedicated contact surface may be formed on a peripheral surface that is not part of the peripheral subsurfaces according to this disclosure and does not face the same direction as any of the peripheral subsurfaces.

[0036] On the other hand, considering a cutting element having six peripheral subsurfaces, the non-cut surfaces on two adjacent peripheral subsurfaces may be suitable for use as contact surfaces when the cutting element is mounted in the slot of the thread milling tool body.

[0037] According to some embodiments, each peripheral subsurface includes two non-cutting surfaces that form separate contact surfaces. For example, each peripheral subsurface may include one or more teeth arranged in a row along the peripheral subsurface in the circumferential direction with respect to the central axis of the cutting element, a non-cutting surface located adjacent to a first main surface (i.e., between the first main surface and the row of threading teeth), and another non-cutting surface located adjacent to a second main surface (i.e., between the second main surface and the row of threading teeth). One or both of these non-cutting surfaces may be used as contact surfaces when the cutting element is mounted in the slot of the threading milling tool body. Therefore, if both of these non-cutting surfaces are used as contact surfaces, a total of four contact surfaces will abut the corresponding support surfaces in the slot of the threading milling tool body when the cutting element is mounted in the slot of the threading milling tool body.

[0038] According to some embodiments, at least one contact surface of each peripheral subsurface has a different length from at least one of the contact surfaces of any adjacent peripheral subsurfaces along the peripheral surface. This prevents incorrect mounting of the cutting element within the slot, as the slot of the thread milling tool into which the cutting element is mounted has corresponding support surfaces of different lengths, and the cutting element can only be mounted in the slot at a limited number of positions.

[0039] In another embodiment, the present invention relates to a thread cutting tool having a tool body having a front end in which a slot is formed, a rear end, and a central axis extending from the front end to the rear end, wherein the thread cutting tool comprises cutting elements according to any embodiment described herein, disposed within the slot, such that teeth included in both of one of a pair of opposing outer peripheral subsurfaces are positioned in an operating position for milling threads into a workpiece, while teeth included in the other outer peripheral subsurface are positioned in a non-operating position.

[0040] Therefore, when a cutting element is mounted in a specific orientation within the slot of the threading milling tool body, only the teeth of a pair of peripheral surfaces are actuated. Thus, as an example, a cutting element with two pairs of peripheral surfaces (i.e., four peripheral surfaces) can be used in two different orientations (allowing for two indexings), while a cutting element with three pairs of peripheral surfaces (i.e., six peripheral surfaces) can be used in three different orientations (allowing for three indexings).

[0041] None of the teeth positioned in a non-working position interfere with the threading operation. The precise arrangement to ensure this depends, for example, on the number of threading teeth and the size of each threading tooth (i.e., the type of thread being machined), the number of peripheral surfaces (i.e., the angle between adjacent peripheral surfaces), and the length of each peripheral surface.

[0042] The tool body may be made of a material different from the cutting element, such as steel. The rear end of the tool body may be adapted to be fixed directly or indirectly to the machine interface of a machine tool, such as a computer numerical control (CNC) machine tool.

[0043] The cutting element may be positioned within a slot in the tool body such that the central axis of the cutting element is perpendicular or substantially perpendicular to the central axis of the tool body.

[0044] Each threading tooth positioned in the working position protrudes perpendicular or substantially perpendicular to the central axis of the thread milling tool. In other words, each of the two peripheral surfaces containing the threading teeth in the working position is oriented perpendicular or substantially perpendicular to the central axis of the thread milling tool. By rotating such a thread milling tool around its central axis, a circular tilting motion can be applied to the tool, allowing threads, such as female threads into holes in the workpiece, to be milled.

[0045] According to some embodiments, the thread cutting tool body further comprises first and second support surfaces positioned within a slot and abutting first and second contact surfaces on a cutting element, respectively, wherein each of the first and second contact surfaces and the first and second support surfaces is oriented obliquely to the central axis of the thread cutting tool.

[0046] This ensures that the cutting element is stably housed within the slot of the threading milling tool body, preventing any displacement of the cutting element within the slot. Screws, clamps, or other fastening elements may be used to secure the cutting element in place.

[0047] Further possible features and advantages of this solution will become apparent from the detailed explanation below. [Brief explanation of the drawing]

[0048] Here, the solution will be described in more detail with reference to the attached drawings, using exemplary embodiments. [Figure 1] This is a perspective view of a cutting element according to a first embodiment of the present invention. [Figure 2] This is a plan view of the first main surface of the cutting element shown in Figure 1. [Figure 3] Figures 1 and 2 show the cutting element, and Figure 2 is a side view of the cutting element as seen from the right towards the outer surface of the cutting element. [Figure 4] This is a perspective view of the threading milling tool body. [Figure 5] Figure 4 shows the thread cutting tool body, and Figures 1 to 3 show the thread cutting tool equipped with the cutting elements. [Figure 6] This is a perspective view of a cutting element according to the second embodiment. [Figure 7] This figure corresponds to Figure 1 and shows a cutting element according to the third embodiment. [Figure 8] This figure corresponds to Figure 2 and shows a cutting element according to the third embodiment. [Figure 9] This figure corresponds to Figure 3 and shows the cutting element according to the third embodiment. All figures are schematic and not necessarily to scale, and generally only the parts necessary to illustrate each embodiment are shown, while other parts are omitted or merely suggested. Unless otherwise indicated, the same reference numerals refer to the same parts in different figures. [Modes for carrying out the invention]

[0049] Figures 1 to 3 show a cutting element 1 according to the first embodiment. The cutting element 1 comprises a first main surface 2, a second main surface 3, and an outer peripheral surface 4. The outer peripheral surface 4 includes six outer peripheral sub-surfaces 5, 5', 6, 6', 7, and 7' arranged in pairs on the opposite side of the cutting element 1, as seen in Figure 2, and facing in the opposite direction when viewed in a plan view of the first main surface. The cutting element further comprises a through hole 8 extending from the first main surface 2 to the second main surface 3 along the central axis C of the cutting element.

[0050] Each of the outer peripheral subsurfaces 5, 5', 6, 6', 7, and 7' is provided with three threaded teeth 9. Each tooth 9 comprises a rake face 15, a relief face 16, and a cutting edge 17 formed at the intersection of the rake face 15 and the relief face 16.

[0051] For each pair of outer peripheral subsurfaces 5, 5', 6, 6', 7, and 7', the teeth 9 on one subsurface 5, 6, and 7 have a rake face 15 facing a first direction S1 (shown in Figure 3), while the teeth 9 on the other subsurface 5', 6', and 7' have a rake face 15 facing a second direction S2 opposite to the first direction S1.

[0052] Figure 4 shows a tool body 10 having a slot 11 in which a cutting element 1 can be placed, and Figure 5 shows a thread milling tool including the tool body 10 and the cutting element 1. The tool body 10 has a front end 12, a rear end 13, and a central axis L of the tool body. The cutting element 1 is fixed in the slot 11 by a screw 25 that extends through a hole 26 in the tool body on one side of the slot, further extends through a through hole 8 of the cutting element, and engages with a screw hole 27 on the other side of the slot.

[0053] As shown in Figure 5, the cutting element 1 is mounted in a slot 11 of the tool body 10 such that both subsurfaces of one pair of outer peripheral subsurfaces 5, 5' are oriented perpendicular to the tool body central axis L. These two outer peripheral subsurfaces 5, 5' are in the working position, i.e., their cutting teeth 9 cut threads into the workpiece, when a threading milling tool is used and rotated around the tool body central axis L in the rotational direction R. The cutting teeth 9 of the other outer peripheral subsurfaces 6, 6', 7, 7', including the cutting teeth 9 of the outer peripheral subsurfaces 6', 7 which extend partially forward from the slot, are in the non-working position and do not interfere with the cutting process.

[0054] Each of the outer peripheral subsurfaces 5, 5', 6, 6', 7, 7' of the cutting element includes two non-cutting surfaces 18, 19 of different lengths, as is best seen in Figure 3. These non-cutting surfaces are flat and are used as contact surfaces positioned to abut against the respective support surfaces 21, 22 within the slot 11 of the tool body 10, as shown in Figure 4. When the cutting element is mounted in the slot, the four contact surfaces 18, 19 on the two adjacent outer peripheral subsurfaces 6, 7' in the non-working position abut against the respective support surfaces 21, 22 within the slot.

[0055] Because the contact surfaces 18, 19 and the corresponding support surfaces 21, 22 have different lengths, the cutting element cannot be mistakenly mounted in the slot. In other words, the cutting element can only be mounted for machining in the rotational direction R shown in Figure 5. As a result, if the operable threading teeth on the active outer peripheral subsurfaces 5, 5' wear out and it is necessary to index the cutting element (i.e., to position new threading teeth in the operating position), the cutting element 1 must be removed from the slot 11, then rotated by an angle of 120° around its central axis C, and then mounted again in the slot 11.

[0056] Figure 6 shows a cutting element 30 according to a second embodiment. This cutting element also includes six peripheral subsurfaces, three of which each contain three threading teeth 9, while each of the intermediate peripheral subsurfaces contains only a flat non-cutting surface 31 and does not contain any cutting teeth. Such a cutting element 30 is still capable of three indexing passes. However, a thread milling tool using such a cutting element 30 has reduced productivity compared to the embodiments described with reference to Figures 1 to 5, because only one set of cutting teeth 9 engages with the workpiece for each rotation of the thread milling tool. Each of the flat non-cutting surfaces 31 functions as a contact surface positioned to abut against the corresponding support surface in the slot of the tool body when the cutting element 30 is mounted therein, as described above with reference to the first embodiment. Each of the peripheral subsurfaces containing the threading teeth 9 further includes a number of small non-cutting surfaces 32 which also function as contact surfaces positioned to abut against the support surface of the thread milling tool body.

[0057] Figures 7 to 9 show a cutting element 60 according to a third embodiment. As is best seen in Figures 7 and 9, the cutting element comprises two separate cutting element portions 30A and 30B, each identical to the cutting element 30 shown in Figure 6, and the cutting element portions 30A and 30B are fixed relative to each other when mounted in the slot of the tool body. By combining the cutting element portions 30A and 30B to form the cutting element 60, each outer peripheral subsurface comprises three threading teeth 9, three small non-cutting contact surfaces 32 (from one outer peripheral subsurface of portions 30A and 30B), and a large, flat non-cutting contact surface 31 (from the other outer peripheral subsurface of portions 30A and 30B). In this embodiment, the central neutral surface P of the cutting element 60 corresponds to the contact surface between the cutting element portions 30A and 30B. The combination of the two parts 30A and 30B yields a cutting element similar to that of the first embodiment described with reference to Figures 1 to 5, so that when the cutting element is mounted on the thread milling tool body, two sets of cutting teeth 9 are in the working position. In other embodiments, the outer peripheral subsurfaces are arranged in pairs on the opposite side of the cutting element 60, as best seen in Figure 8, and face in opposite directions when viewed in a plan view of the first main surface. As seen in Figure 7, the rake face 15 of each tooth 9 is provided with a chip groove, resulting in a larger positive rake angle. The chip grooves provide improved chip formation control and can reduce cutting force and temperature during machining.

[0058] The above description contains several specificities, but these should not be interpreted as limiting the scope of the concepts described herein, but merely as providing examples of some exemplary embodiments of the concepts described. It will be understood that the scope of the concepts described now fully encompasses other embodiments that may be obvious to those skilled in the art, and that the scope of the concepts described now should not be limited.

Claims

1. A cutting element (1, 30, 60) for a threading milling tool, - The first and second main surfaces (2, 3) are arranged opposite each other and facing in opposite directions, - The outer peripheral surface (4) connecting the first main surface and the second main surface, the outer peripheral surface (4) including an even number of outer peripheral sub-surfaces (5, 5', 6, 6', 7, 7') arranged in pairs on both sides of the cutting element and facing in opposite directions. Equipped with, A cutting element (1, 30, 60) characterized in that each pair of outer peripheral subsurfaces includes one or more threading teeth (9) having a rake face (15) on one of the subsurfaces facing a first direction (S1), and one or more threading teeth (9) having a non-cutting surface (18, 19, 31, 32) and / or a rake face (15) on the opposite subsurface facing a second direction (S2), wherein the second direction (S2) is opposite to the first direction (S1), and the number of outer peripheral subsurfaces is at least four.

2. The cutting element according to claim 1, wherein the number of the outer peripheral subsurfaces is six.

3. The cutting element according to claim 1 or 2, wherein each of the outer peripheral subsurfaces includes one or more non-cut surfaces and one or more threaded teeth.

4. The cutting element according to any one of claims 1 to 3, wherein each of the outer peripheral subsurfaces includes two or more threaded teeth arranged in a row along the outer peripheral subsurface.

5. A cutting element according to any one of claims 1 to 4, wherein the directions in which two adjacent peripheral subsurfaces are oriented along the peripheral surface differ by an angle equal to the value obtained by dividing 360° by the total number of peripheral subsurfaces when the first or second main surface is viewed in a plan view.

6. A cutting element according to any one of claims 1 to 5, wherein each rake face is provided with a chip groove.

7. The cutting element according to any one of claims 1 to 6, wherein the cutting element is an integrated body.

8. The cutting element according to any one of claims 1 to 6, comprising two separate parts (30A, 30B) that are detachably arranged from each other.

9. A cutting element according to any one of claims 1 to 8, comprising at least two contact surfaces that are oriented in different directions and are arranged to contact the respective support surfaces (21, 22) of the tool body within the slot, in order to prevent displacement of the cutting element relative to the tool body (10) when the cutting element is mounted in the slot (11).

10. The cutting element according to claims 9 and 3, wherein the contact surface is formed by the non-cut surface included in the outer peripheral subsurface.

11. The cutting element according to claim 10, wherein each outer peripheral subsurface includes two non-cut surfaces that form separate contact surfaces.

12. The cutting element according to claim 10 or 11, wherein for each peripheral subsurface, at least one of the contact surfaces has a different length from at least one of the contact surfaces of any of the adjacent peripheral subsurfaces along the peripheral surface.

13. A thread cutting milling tool comprising a tool body (10) having a front end (12) in which a slot (11) is formed, a rear end (13), and a central axis (L) extending from the front end to the rear end, wherein the thread cutting milling tool comprises cutting elements (1, 30, 60) according to any one of claims 1 to 12 disposed in the slot (11), so that the teeth (9) included in both of the pair of opposing outer peripheral subsurfaces are positioned in an operating position for milling threads in a workpiece, while the teeth included in the other outer peripheral subsurface are positioned in a non-operating position.

14. A thread cutting tool according to claim 13, comprising a cutting element according to any one of claims 9 to 12, further comprising first and second support surfaces (21, 22) that abut against the first and second contact surfaces of the at least two contact surfaces, respectively, wherein the first and second contact surfaces and the first and second support surfaces are oriented obliquely to the central axis (L) of the thread cutting tool.

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