Cutting tool and method for manufacturing machined product

Abstract

A cutting tool according to a non-limiting aspect of the present disclosure has a rod-shaped holder and a cutting insert attached to the holder. The holder has a first member that has a first uneven surface, a second member that has a second uneven surface which fits with the first uneven surface, and a fixing screw that fixes the second member to the first member. The second member has an upper jaw section, a lower jaw section, a pocket, a connection section positioned on the rear end side and including the second uneven surface, and a slit located between the upper jaw section and the connection section. The lower jaw section is fixed to the connection section. The upper jaw section is separated from the connection section via the slit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2022-038894, filed on March 14, 2022, the entire disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a cutting tool used in cutting a workpiece and a method for manufacturing a cut product. Examples of cutting include turning and milling. Examples of turning include internal diameter machining, external diameter machining, grooving, and cut-off. [Background technology]

[0003] An example of a cutting tool used when cutting a workpiece is the cutting tool described in International Publication No. 2003 / 106084 (Patent Document 1). The cutting tool described in Patent Document 1 has a holder and an insert. The holder has a base and a head. The head has an upper jaw and a lower jaw, and a pocket into which the insert is inserted is formed between the upper jaw and the lower jaw. In addition, serrations are provided on the surfaces of the base and the head where they abut against each other.

[0004] To insert the insert into the pocket, the upper jaw needs to move relative to the lower jaw. Therefore, it is not possible to provide serrations on the entire surface of the head facing the base, and the area of ​​the head facing the base that corresponds to the upper jaw must not have serrations. This hinders the head from being firmly fixed to the base, making it difficult to increase the strength of the holder. Summary of the Invention

[0005] A non-limiting one-sided cutting tool of the present disclosure includes a rod-shaped holder extending from a front end to a rear end, and a cutting insert attached to the front end of the holder. The holder includes a rod-shaped first member located near the rear end and having a first uneven surface on the front end side, a second member located near the front end and having a second uneven surface on the rear end side that fits into the first uneven surface, and a fixing screw that fixes the second member to the first member.

[0006] The second member has an upper jaw portion located on the tip side, a lower jaw portion located on the tip side and facing the upper jaw portion, a pocket located between the upper jaw portion and the lower jaw portion and capable of receiving the cutting insert, a connecting portion located on the rear end side and including the second uneven surface, and a slit located between the upper jaw portion and the connecting portion. The lower jaw portion is fixed to the connecting portion. The upper jaw portion is separated from the connecting portion via the slit. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a non-limiting one-sided cutting tool of the present disclosure. [Figure 2] FIG. 2 is an enlarged view of an area II shown in FIG. [Figure 3] FIG. 2 is a side view of the cutting tool shown in FIG. [Figure 4] FIG. 4 is an enlarged view of an area IV shown in FIG. [Figure 5] 2 is an exploded perspective view of a cutting insert, a second member, and a clamp screw of the cutting tool shown in FIG. 1. FIG. [Figure 6] 2 is a perspective view of a second member of the cutting tool shown in FIG. 1, as viewed from the tip side. FIG. [Figure 7] 7 is a perspective view of the second member shown in FIG. 6 as viewed from the rear end side. FIG. [Figure 8] 7 is a plan view of the second member shown in FIG. 6 as viewed from the tip end side. [Figure 9] 7 is a plan view of the second member shown in FIG. 6 as seen from the rear end side. [Figure 10] 9 is a side view of the second member shown in FIG. 8 as viewed from the X direction. [Figure 11] 10 is a side view of the second member shown in FIG. 8 as viewed from direction XI. [Figure 12] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. [Figure 13] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. [Figure 14] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. [Figure 15] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] <Cutting tools> A non-limiting embodiment of the cutting tool 1 of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, the drawings below show only the main components necessary for explaining the embodiment in a simplified form. Therefore, the cutting tool 1 may include optional components not shown in the drawings. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components or the dimensional ratios of the components.

[0009] The cutting tool 1 may include a holder 3 and a cutting insert 5, as a non-limiting example shown in FIGS.

[0010] The holder 3 may be rod-shaped. For example, the holder 3 may be cylindrical. The cylindrical shape may be roughly cylindrical, and does not necessarily have to be cylindrical in the strict sense. The holder 3 may also extend from the front end 3a to the rear end 3b. The holder 3 may extend from the front end 3a to the rear end 3b along the central axis O1.

[0011] The size of the holder 3 is not limited to a specific size. For example, the length of the holder 3 in the direction along the central axis O1 may be set to approximately 150 to 450 mm. The width (diameter) of the holder 3 in the direction perpendicular to the central axis O1 may be set to approximately 10 to 50 mm.

[0012] The cutting insert 5 may simply be referred to as the insert 5. The insert 5 can be used to cut a workpiece in a cutting process. The insert 5 may have a columnar shape. For example, the insert 5 may have a prismatic shape. The prismatic shape may be roughly a prismatic shape, and does not necessarily have to be a prismatic shape in the strict sense. The insert 5 may also have a cutting edge 7. The cutting edge 7 may be located at an end of the insert 5 in the longitudinal direction.

[0013] The insert 5 may be attached to the tip 3a of the holder 3. The insert 5 may be attached to the holder 3 so that the cutting edge 7 protrudes laterally from the tip 3a of the holder 3. The cutting tool 1 can perform cutting by bringing the cutting edge 7 into contact with a workpiece.

[0014] 3, the cutting edge 7 may be located at the farthest position from the central axis O1 at the tip 3a of the holder 3. When the cutting edge 7 protrudes laterally in this manner, only the vicinity of the cutting edge 7 can be brought into contact with the workpiece.

[0015] The holder 3 may be made up of a plurality of members. The holder 3 may have a first member 9, a second member 11, and a fixing screw 13, as shown in a non-limiting example in FIG.

[0016] The first member 9 may be rod-shaped. The first member 9 may be located on the rear end 3b side and have a first uneven surface 15 on the front end 3a side (see FIGS. 2 and 4). The first member 9 may function as a member gripped by a machine tool. The first member 9 may also be called a shank.

[0017] The first uneven surface 15 may be configured, for example, by a plurality of grooves extending parallel to one another. In this case, the extension direction of the plurality of grooves in the first uneven surface 15 may be the same as the protruding direction of the cutting edge 7 of the insert 5. In addition, when the insert 5 has a columnar shape, the protruding direction of the cutting edge 7 of the insert 5 may be rephrased as the longitudinal direction of the insert 5. The depths of the plurality of grooves in the first uneven surface 15 may be the same or different from one another.

[0018] The second member 11 may have a second uneven surface 17 located on the side of the front end 3a and mating with the first uneven surface 15 on the side of the rear end 3b. The second member 11 may function as a member for fixing the insert 5. The second member 11 may also be called a head. The second member 11 may be plate-shaped.

[0019] The second uneven surface 17 may be formed, for example, by a plurality of grooves extending parallel to one another, similar to the first uneven surface 15. In this case, the extension direction of the plurality of grooves in the second uneven surface 17 may be the same as the protruding direction of the cutting edge 7 of the insert 5. When the first uneven surface 15 and the second uneven surface 17 are each formed by a plurality of grooves, the plurality of grooves in the first uneven surface 15 and the plurality of grooves in the second uneven surface 17 may be fitted together so as to mesh with one another. The depths of the plurality of grooves in the second uneven surface 17 may be the same or different from one another.

[0020] The first uneven surface 15 and the second uneven surface 17 in the non-limiting example shown in Fig. 2 may also be called serrations. Serrations may refer to sawtooth-shaped unevenness formed by a plurality of grooves extending in parallel.

[0021] The fixing screw 13 may be a member that fixes the second member 11 to the first member 9. There may be only one fixing screw 13, or there may be multiple fixing screws 13.

[0022] The second member 11 may have an upper jaw portion 19, a lower jaw portion 21, a pocket 23, a connecting portion 25, and a slit 27, as a non-limiting example shown in FIGS.

[0023] The upper jaw portion 19 may be located on the side of the tip 3 a of the second member 11. The lower jaw portion 21 may be located on the side of the tip 3 a of the second member 11, or may be opposite the upper jaw portion 19. As shown in a non-limiting example in FIG. 2 , the upper jaw portion 19 and the lower jaw portion 21 can come into contact with the insert 5 when the insert 5 is attached to the holder 3, and can clamp the insert 5.

[0024] The upper jaw portion 19 and the lower jaw portion 21 are used for convenience and do not indicate an up and down direction. For example, the upper jaw portion 19 does not need to face upward when using the cutting tool 1. These points are the same for other parts that include the expressions up and down.

[0025] The pocket 23 may be located between the upper jaw portion 19 and the lower jaw portion 21. An insert 5 can be attached to the pocket 23. By inserting the insert 5 into the pocket 23 and abutting the upper jaw portion 19 and the lower jaw portion 21 against the insert 5, the insert 5 can be gripped by the upper jaw portion 19 and the lower jaw portion 21.

[0026] As described above, when the first uneven surface 15 and the second uneven surface 17 are each formed of a plurality of grooves extending parallel to one another, these grooves may extend parallel to the pocket 23. This increases the holding force of the plurality of grooves against the largest principal component of cutting loads applied to the cutting tool 1 during cutting. Note that the term "parallel" does not require strict precision, and it is acceptable for the plurality of grooves to be slightly inclined (about 5°) relative to the pocket 23.

[0027] The connecting portion 25 may be located on the rear end 3b side of the second member 11, and may include the second uneven surface 17. The connecting portion 25 can function as a portion that connects the second member 11 to the first member 9. The slit 27 may be located between the upper jaw portion 19 and the connecting portion 25.

[0028] 7 and 10, the lower jaw 21 may be fixed to the connecting portion 25. Alternatively, the upper jaw 19 may be separated from the connecting portion 25 via a slit 27. This allows the upper jaw 19 to move more easily in the up and down direction, making it easier to attach and detach the insert 5.

[0029] In the above case, as shown in a non-limiting example in FIG. 9 , it is possible to form a larger portion of the second uneven surface 17 on the surface of the connecting portion 25 facing the first uneven surface 15, corresponding to the region A corresponding to the upper jaw portion 19. That is, when the lower jaw portion 21 is fixed to the connecting portion 25 and the upper jaw portion 19 moves away from the connecting portion 25 through the slit 27, the upper jaw portion 19 becomes elastically deformable so as to move relative to the lower jaw portion 21. It is also possible to provide the second uneven surface 17 on the entire surface of the connecting portion 25 facing the first uneven surface 15. This makes it possible to firmly fix the second member 11 to the first member 9. Therefore, the cutting tool 1 provides the holder 3 with high strength.

[0030] The slit 27 may be located only between the upper jaw 19 and the connecting portion 25, or as shown in Fig. 10, a part of the slit 27 may be located between the lower jaw 21 and the connecting portion 25. When the second member 11 is fabricated so that the upper jaw 19 is separated from the connecting portion 25 via the slit 27, the process of forming the slit 27 becomes easier.

[0031] Upper jaw portion 19 may have an upper through-hole 29, as shown in a non-limiting example in Figure 8. Upper through-hole 29 may open toward lower jaw portion 21. Lower jaw portion 21 may also have a screw hole 31. Screw hole 31 may open toward upper through-hole 29.

[0032] 2, the second member 11 may further include a clamp screw 33. The clamp screw 33 may be inserted into the upper through-hole 29 and the screw hole 31. The clamp screw 33 may be a member that fixes the upper jaw portion 19 to the lower jaw portion 21.

[0033] In these cases, the insert 5 can be fixed in the pocket 23 by tightening the clamp screw 33 inserted into the upper through-hole 29 and the screw hole 31. That is, the insert 5 can be fixed in the pocket 23 by tightening the clamp screw 33 with the insert 5 held by the upper jaw 19 and the lower jaw 21, and elastically deforming the upper jaw 19 to press it down, thereby obtaining a clamping force. In addition, the clamping force can be adjusted by tightening the clamp screw 33.

[0034] The clamp screw 33 may be inserted into the upper through hole 29 and the screw hole 31 so as to intersect with the central axis O1 (see FIG. 8). In this case, it is easy to increase the length of the portion formed by the upper through hole 29 and the screw hole 31 into which the clamp screw 33 is inserted. This makes it possible to increase the restraining force of the clamp screw 33 on the insert 5.

[0035] As shown in a non-limiting example in FIG. 8, the lower jaw portion 21 may further have a first through hole 35 and a second through hole 37. The first through hole 35 and the second through hole 37 may each extend from the front end 3a toward the rear end 3b. Furthermore, as shown in a non-limiting example in FIG. 9, the connecting portion 25 may have a third through hole 39 and a fourth through hole 41. The third through hole 39 may open toward the first through hole 35. The fourth through hole 41 may open toward the second through hole 37. The third through hole 39 may be connected to the first through hole 35, and the fourth through hole 41 may be connected to the second through hole 37.

[0036] 2, the fixing screw 13 may include a first fixing screw 43 and a second fixing screw 45. The first fixing screw 43 may be inserted into the first through hole 35 and the third through hole 39. The second fixing screw 45 may be inserted into the second through hole 37 and the fourth through hole 41.

[0037] 8, the screw hole 31 may extend between the first through hole 35 and the second through hole 37. In this case, it is easy to increase the length of the screw hole 31, which makes it easy to ensure a clamping force.

[0038] The first fixing screw 43 and the second fixing screw 45 may be the same material as the clamp screw 33, or different materials may be used. As a non-limiting example shown in FIG. 2, the diameter D1 of the first fixing screw 43 and the second fixing screw 45 may be larger than the diameter D2 of the clamp screw 33. When the diameter D2 of the clamp screw 33 is relatively small (thin), the strength of the upper jaw portion 19 is easily ensured. Furthermore, when the diameter D1 of the first fixing screw 43 and the second fixing screw 45 is relatively large (thick), the second member 11 can be firmly fixed to the first member 9.

[0039] As shown in a non-limiting example in FIG. 8, the upper jaw portion 19 may further include a fifth through hole 47 extending from the front end 3 a toward the rear end 3 b. Furthermore, as shown in a non-limiting example in FIG. 9, the connecting portion 25 may further include a sixth through hole 49 opening toward the fifth through hole 47. As shown in a non-limiting example in FIG. 2, the fixing screw 13 may further include a third fixing screw 51 inserted into the fifth through hole 47 and the sixth through hole 49. In these cases, the fixing state of the second member 11 relative to the first member 9 is more likely to be stable. Furthermore, the sixth through hole 49 may be connected to the fifth through hole 47.

[0040] The second through hole 37 and the fifth through hole 47 may be located closer to the pocket 23 than the portion where the upper jaw 19 and the lower jaw 21 are connected. The cutting load applied to the portion where the upper jaw 19 and the lower jaw 21 are connected and to the clamp screw 33 can be distributed to the second fixing screw 45 and the third fixing screw 51. This makes it possible to improve the durability of the holder 3.

[0041] In the direction from the front end 3a to the rear end 3b, the width W1 of the upper jaw portion 19 and the width W2 of the connecting portion 25 may each be larger than the width W0 of the slit 27. In this case, the rigidity of the upper jaw portion 19 and the connecting portion 25 is easily maintained. Therefore, the rigidity of the second member 11 is easily ensured. In this case, the width W1 of the upper jaw portion 19 may be the same as the width W2 of the connecting portion 25, or they may be different. For example, as in a non-limiting example shown in FIG. 10, the width W1 of the upper jaw portion 19 may be larger than the width W2 of the connecting portion 25. In this case, the rigidity of the upper jaw portion 19 is easily maintained. Therefore, the clamping force is easily ensured.

[0042] The width W1 of the upper jaw portion 19 and the width W2 of the connecting portion 25 are not limited to a specific size. For example, the width W1 may be set to about 5 to 10 mm. The width W2 may be set to about 5 to 10 mm. The width W1 may be evaluated as a maximum value. The width W2 may be evaluated as a maximum value at a portion facing the upper jaw portion 19.

[0043] 8 and 10, the bottom surface 53 of the slit 27 may extend parallel to the pocket 23. In this case, it is easy to move the upper jaw portion 19 in the vertical direction relative to the lower jaw portion 21, and it is easy to ensure the thickness of the second member 11 in the vertical direction near the boundary between the lower jaw portion 21 and the connecting portion 25. As a result, it is easy to attach the insert 5 to the pocket 23, and it is easy to ensure the strength of the second member 11.

[0044] The above configuration may be evaluated by viewing from the tip 3a side in a planar perspective view, as in a non-limiting example shown in Figure 8. Furthermore, "parallel" does not necessarily mean "strictly parallel" but may mean allowing an inclination of about ±5°.

[0045] The respective concaves and convexes in the first uneven surface 15 and the second uneven surface 17 may extend parallel to the pocket 23. Specifically, as in a non-limiting example shown in FIGS. 2 and 7 , the plurality of grooves in the first uneven surface 15 and the second uneven surface 17 may extend parallel to the pocket 23. During cutting, a relatively large cutting load is likely to be applied in a direction perpendicular to the pocket 23. However, in the above case, the first uneven surface 15 and the second uneven surface 17 are likely to withstand the above-mentioned relatively large cutting load. Therefore, the durability of the holder 3 is high.

[0046] The lower jaw portion 21 may be formed integrally with the connecting portion 25, as in a non-limiting example shown in Figure 10. In this case, the strength of the second member 11 is high.

[0047] When viewed from the rear end 3b side in a plan view, connecting portion 25 may overlap at least a part of upper jaw portion 19 (see FIG. 9). Furthermore, when viewed from the rear end 3b side in a plan view, second uneven surface 17 may overlap at least a part of upper jaw portion 19 (see FIG. 9).

[0048] Examples of materials for the holder 3 include steel and cast iron. When the material for the holder 3 is steel, the holder 3 has high toughness.

[0049] Examples of the material of the insert 5 include cemented carbide and cermet. Examples of the cemented carbide composition include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. Here, WC, TiC, and TaC may be hard particles, and Co may be a binder phase.

[0050] The cermet may be a sintered composite material in which a ceramic component is combined with a metal. An example of a cermet is a titanium compound mainly composed of titanium carbide (TiC) or titanium nitride (TiN). It goes without saying that the material of the insert 5 is not limited to the above composition.

[0051] The surface of the insert 5 may be coated with a coating using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. The coating composition may include, for example, titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al2O3).

[0052] <Method of manufacturing machined products> Next, a non-limiting method for manufacturing the one-surface machined product 101 according to the present disclosure will be described with reference to FIGS.

[0053] The machined product 101 may be produced by cutting a workpiece 103. A method for producing the machined product 101 may include the following steps: (1) rotating the workpiece 103; (2) bringing the cutting tool 1, which is typified by the non-limiting embodiment described above, into contact with the rotating workpiece 103; (3) a step of separating the cutting tool 1 from the workpiece 103; may also be provided.

[0054] Specifically, first, as in a non-limiting example shown in Figures 12 and 13, the workpiece 103 may be rotated around the axis O2 and the cutting tool 1 may be brought relatively close to the workpiece 103. Next, as in a non-limiting example shown in Figure 14, the insert 5 (cutting edge 7) of the cutting tool 1 may be brought into contact with the workpiece 103 to cut the workpiece 103. Then, as in a non-limiting example shown in Figure 15, the cutting tool 1 may be moved relatively away from the workpiece 103.

[0055] By going through the above steps, it is possible to obtain a machined product 101 with a highly accurate finished surface. Specifically, when the cutting tool 1 is used in the manufacturing method of the machined product 101, the high strength of the holder 3 makes it possible to exhibit excellent machinability. As a result, it is possible to obtain a machined product 101 with a highly accurate finished surface. Furthermore, the high strength of the holder 3 makes it possible to exhibit excellent machinability over a long period of time. As a result, the frequency of replacement of the holder 3 is reduced, which is also economical.

[0056] In the non-limiting example shown in Figures 12 to 15, in each process, the cutting tool 1 is moved to bring the cutting tool 1 into contact with the workpiece 103 or to move the cutting tool 1 away from the workpiece 103, but of course, the present invention is not limited to this form.

[0057] For example, in step (1), the workpiece 103 may be brought closer to the cutting tool 1. Similarly, in step (3), the workpiece 103 may be moved away from the cutting tool 1. When continuing the cutting process, the workpiece 103 may be kept rotating, and the step of bringing the insert 5 (cutting edge 7) of the cutting tool 1 into contact with different locations on the workpiece 103 may be repeated.

[0058] Examples of the material of the workpiece 103 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals. [Explanation of symbols]

[0059] 1...cutting tools 3. Holder 3a...Tip 3b...rear end 5. Cutting insert (insert) 7. Cutting edge 9. First member 11... Second member 13 Fixing screw 15...1st uneven surface 17...Second uneven surface 19. Upper jaw 21 Lower jaw 23. Pocket 25 Connection 27. Slit 29...Top through hole 31 Screw hole 33 Clamp screw 35 First through hole 37 Second through hole 39 Third through hole 41...Fourth through hole 43···First fixing screw 45···Second fixing screw 47 5th through hole 49...6th through hole 51···Third fixing screw 53 Bottom 101...Cutting workpiece 103...Work material O1...center axis O2 axis

Claims

1. a rod-shaped holder extending along a central axis from a front end to a rear end; a cutting insert attached to the tip of the holder, The holder is a rod-shaped first member located on the rear end side and having a first uneven surface on the front end side; a second member located on the front end side and having a second concave-convex surface on the rear end side that fits with the first concave-convex surface; a fixing screw for fixing the second member to the first member, The second member is an upper jaw portion located on the tip side; a lower jaw portion located on the tip side and facing the upper jaw portion; a pocket located between the upper jaw portion and the lower jaw portion, into which the cutting insert can be attached; a connection portion located on the rear end side and including the second uneven surface; a slit located between the upper jaw portion and the connecting portion, the lower jaw portion is fixed to the connecting portion, the upper jaw portion is separated from the connecting portion through the slit, the upper jaw portion has an upper through-hole that opens toward the lower jaw portion, the lower jaw portion has a screw hole that opens toward the upper through hole, the second member further includes a clamp screw inserted into the upper through hole and the screw hole to fix the upper jaw portion to the lower jaw portion; the lower jaw portion further includes a first through hole and a second through hole extending from the front end toward the rear end, The connection portion is a third through hole that opens toward the first through hole; a fourth through hole that opens toward the second through hole, The fixing screw a first fixing screw inserted into the first through hole and the third through hole; a second fixing screw inserted into the second through hole and the fourth through hole, the screw hole extends between the first through hole and the second through hole, A cutting tool wherein the clamp screw is inserted into the upper through hole and the screw fixing hole so as to be inclined with respect to an imaginary line perpendicular to the pocket when viewed from the front from the tip side and so as to intersect with the central axis.

2. The cutting tool according to claim 1 , wherein the diameters of the first and second set screws are larger than the diameter of the clamp screw.

3. the upper jaw portion further has a fifth through hole extending from the front end toward the rear end, the connecting portion further includes a sixth through hole that opens toward the fifth through hole, The fixing screws further include a third fixing screw inserted into the fifth through hole and the sixth through hole, The cutting tool according to claim 1 , wherein the second through hole and the fifth through hole are located closer to the pocket than a portion where the upper jaw portion and the lower jaw portion are connected.

4. The cutting tool according to claim 1 , wherein a width of the upper jaw portion and the connecting portion in a direction from the front end to the rear end is greater than a width of the slit.

5. The cutting tool according to claim 4 , wherein a width of the upper jaw portion is greater than a width of the connecting portion in a direction from the front end to the rear end.

6. The cutting tool according to claim 1 , wherein a bottom surface of the slit extends parallel to the pocket.

7. the first uneven surface and the second uneven surface are each formed by a plurality of grooves extending parallel to each other; The cutting tool of claim 1 , wherein the groove extends parallel to the pocket.

8. The cutting tool of claim 1 , wherein a portion of the slit is located between the lower jaw portion and the connecting portion.

9. rotating the workpiece; a step of bringing the cutting tool according to any one of claims 1 to 8 into contact with the rotating workpiece; and removing the cutting tool from the workpiece.

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