Patent ID: 12257638

EMBODIMENTS

Cutting inserts1(inserts1) in non-limiting embodiments may be described in detail below with reference to the drawings. For the sake of description, the drawings referred to in the following may illustrate, in simplified form, only main members necessary for describing the non-limiting embodiments. The following inserts1may therefore be capable of including any arbitrary structural member not illustrated in the drawings referred to. Dimensions of the members in each of the drawings faithfully may represent neither dimensions of actual structural members nor dimensional ratios of these members.

<Inserts>

The insert1may include, for example, a first surface3, a second surface5, a lateral surface7and a cutting edge9as illustrated inFIG.1. The first surface3may have a polygonal shape including a plurality of corners and a plurality of sides as in a non-limiting embodiment illustrated inFIG.2. The first surface3may have an approximately rectangular shape as in the non-limiting embodiment illustrated inFIG.2.

The second surface5may be located on a side opposite to the first surface3, and may have a polygonal shape including a plurality of corners and a plurality of sides similarly to the first surface3. Similarly to the first surface3, the second surface5may have an approximately rectangular shape. The insert1may have a quadrangular prism shape as illustrated inFIG.1.

As used herein, the term “polygonal shape” may not denote a strict polygonal shape. For example, the four sides of the first surface3may not be individually a strict straight line, but may be slightly curved in a front view of the first surface3. The four corners of the first surface3may not be individually a strict corner.

The first surface3may have a rectangular shape and may include the four corners and the four sides as in the non-limiting embodiment illustrated inFIG.2. The four corners may include a first corner11, a second corner13and a third corner15. The four sides may include a first side17and a second side19. That is, the first surface3may include the first corner11, the second corner13, the third corner15, the first side17and the second side19.

The second corner13and the third corner15may be individually located adjacent to the first corner11. The first side17may be located between the first corner11and the second corner13. In other words, the first side17may be extended from the first corner11toward the second corner13.

The second side19may be located between the first corner11and the third corner15. In other words, the second side19may be extended from the first corner11toward the third corner15. These parts may be located on an outer peripheral edge of the first surface3in the order of the second corner13, the first side17, the first corner11, the second side19and the third corner15in a direction from the second corner13toward the third corner15.

The first corner11is not limited to a strict corner formed by the intersection of the first side17with the second side19. For example, the first corner11may have a convex curvilinear shape that protrudes outward in the front view of the first surface3. Alternatively, the first corner11may have a configuration obtained by combining a straight line and a curved line as in the non-limiting embodiment illustrated inFIG.2. Similarly to the first corner11, the second corner13and the third corner15are not limited to a strict corner.

One of short sides of the first surface3having the rectangular shape may correspond to the first side17in the non-limiting embodiment illustrated inFIG.2. One of long sides of the first surface3having the rectangular shape may correspond to the second side19in the non-limiting embodiment illustrated inFIG.2. Because the first surface3has the rectangular shape in the non-limiting embodiment illustrated inFIG.2, an angle at which an extension line of the first side17intersects with an extension line of the second side19may be approximately 90° in the front view of the first surface3.

An imaginary straight line passing through a center of the first surface3and a center of the second surface5may be a central axis O1. An imaginary plane that is located between the first surface3and the second surface5and is orthogonal to the central axis O1may be a reference plane S1. Because the first surface3has the rectangular shape in the non-limiting embodiment illustrated inFIG.2, an intersection of diagonals of the first surface3may be regarded as the center of the first surface3. Intersection portions of the extension lines of the individual sides constituting the rectangular shape may serve as a starting point of the diagonals.

Similarly, because the second surface5has the rectangular shape in the non-limiting embodiment illustrated inFIG.2, an intersection of diagonals of the second surface5may be regarded as the center of the second surface5. If the first surface3does not have the rectangular shape, the center of the first surface3may be determined, for example, by a position of a center of gravity of the first surface3in the front view of the first surface3.

The first surface3may have rotational symmetry of 180° around the central axis O1in the front view of the first surface3. The second surface5may have rotational symmetry of 180° around the central axis O1in the front view of the second surface5.

The shapes of the first surface3and the second surface5are not limited to the above shape. The first surface3may have an approximately quadrangular shape in a non-limiting embodiment illustrated inFIG.1. Alternatively, the first surface3and the second surface5may have, for example, a triangular shape, pentagonal shape, hexagonal shape or octagonal shape.

The lateral surface7may be located between the first surface3and the second surface5. The lateral surface7may connect to the first surface3and the second surface5as in a non-limiting embodiment illustrated inFIGS.4and5. The insert1may include a cutting edge9located on at least a part of an intersection of the first surface3and the lateral surface7.

The cutting edge9may be usable to cut out a workpiece if the insert1is used to manufacture a machined product. The cutting edge9may be located over the whole or a part of the intersection. The insert1may further include another cutting edge located on at least a part of an intersection of the second surface5and the lateral surface7.

If the cutting edge9is located on at least the part of the insertion of the first surface3and the lateral surface7, one of the first surface3and the lateral surface7may include a rake surface region, and the other may include a flank surface region. The first surface3may include the rake surface region and the lateral surface7may include the flank surface region as in the non-limiting embodiment illustrated inFIG.1.

The cutting edge9may include a first cutting edge21, a second cutting edge23and a first corner cutting edge25as illustrated inFIG.1. The cutting edge9may be usable in a cutting process of a workpiece. The first cutting edge21may be located on the first side17. For example, if the insert1is used to carry out the cutting process of the workpiece, the first cutting edge21may be used as a bottom cutting edge located along a machined surface of the workpiece.

The second cutting edge23may be located on the second side19. The second cutting edge23may be used as an outer peripheral cutting edge. If the first cutting edge21is used as the bottom cutting edge, and the second cutting edge is used as the outer peripheral cutting edge, the second cutting edge23may contribute mainly to the cutting process. The second cutting edge23may therefore be called a main cutting edge9in some cases.

The first corner cutting edge25may be located at the first corner11. The first corner cutting edge25may located over the whole or a part of the first corner11. The first corner cutting edge25may be located over the whole of the first corner11in the embodiment illustrated inFIG.1.

A maximum width of the first surface3may be, for example, 6-25 mm in the front view of the first surface3. A height from the first surface3to the second surface5may be, for example, 5-20 mm. As used herein, the term “height from the first surface3to the second surface5” may denote a maximum value of a distance between the first surface3and the second surface5in a direction parallel to the central axis O1, and may be rephrased as a width of the lateral surface7in a direction along the central axis O1.

The lateral surface7may include a first lateral surface27and a second lateral surface29in the present embodiment as illustrated inFIGS.4and5. At least a part of the first lateral surface27may be located between the first side17and the second surface5. The first lateral surface27may have a planer shape. At least a part of the second lateral surface29may be located between the second side19and the second surface5. The second lateral surface29may have a planar shape.

The first lateral surface27and the second lateral surface29may be used as a surface brought into contact with a holder103if fixing the insert1to the holder. If the first lateral surface27and the second lateral surface29are flat, the insert1may be stably fixable to the holder.

The above flat surface region is not limited to a strict flat surface. These surface regions may be approximately flat, and specifically may be slightly curved or may have slight irregularities, both of which are unremarkable on the whole. More specifically, these surface regions may include slight irregularities of approximately several tens of μm.

The first lateral surface27may be inclined instead of being parallel to the second lateral surface29. The first lateral surface27may be inclined at an angle of approximately 90° with respect to the second lateral surface29in the non-limiting embodiment illustrated inFIG.2because the extension line of the first side17intersects with the extension line of the second side19at an angle of approximately 90° in the front view of the first surface3.

The first lateral surface27may be located further outside than the first side17in the front view of the first surface3. In other words, the first lateral surface27may be located further away from the center of the first surface3than the first side17in the front view of the first surface3. If the first lateral surface27is located further outside than the first side17, the cutting edge9may be less likely to come into contact with the holder if the first lateral surface27is brought into contact with the holder in order to fix the insert1to the holder. The holder and the cutting edge9may therefore be less susceptible to damage.

The first lateral surface27may include a region located closer to the second lateral surface29as coming closer to the second surface5. Hereinafter, this region may be referred to as a first region31. The first region31may be located so as to include an end portion of the first lateral surface27which is located on a side of the second lateral surface29as illustrated inFIG.4. The first region31may also be located so as to include an end portion of the first lateral surface27which is located on a side of the second surface5.

At least a part of an outer peripheral edge of the first lateral surface27which is located on a side of the second lateral surface29may be included in the first region31. In other words, the part of the outer peripheral edge of the first lateral surface27which is included in the first region31may be located closer to the second lateral surface29as coming closer to the second surface5.

As in the non-limiting embodiment illustrated inFIG.2, a first curved surface33having a convex curved surface shape may be located between the first lateral surface27and the second lateral surface29. The first curved surface33may be located between the first corner11and the second surface5as in the non-limiting embodiment illustrated inFIG.5. A boundary part C1between the first lateral surface27and the first curved surface33may be located closer to the second lateral surface29as coming closer to the second surface5as in the non-limiting embodiment illustrated inFIG.4. Specifically, the boundary part C1may extended obliquely in a direction from upper left to lower right as in the non-limiting embodiment illustrated inFIG.4.

The part of the outer peripheral edge of the first lateral surface27which is included in the first region31may be located closer to the second lateral surface29as coming closer to the second surface5. In other words, the part of the outer peripheral edge of the first lateral surface27which is included in the first region31may be located away from the second lateral surface29as coming closer to the first surface3. In this case, the first lateral surface27may be less likely to interfere with the workpiece if the first corner cutting edge25is used to carry out the cutting process of the workpiece. This may facilitate to obtain a smooth finish of a machined surface of the workpiece.

The first lateral surface27may be less likely to interfere with the workpiece and may be less susceptible to wear. Consequently, the insert1may be stably fixable to the holder if the first lateral surface27is brought into contact with the holder in order to fix the insert1to the holder.

As stated earlier, one of the short sides of the first surface3may be the first side17, and one of the long sides of the first surface3may be the second side19. Thus, the first side17may be shorter than the second side19.

If the first side17is shorter than the second side19, the first lateral surface27may tend to have a smaller area than the second lateral surface29. In cases where the first lateral surface27includes the first region31, the insert1may be stably fixable to the holder even if the area of the first lateral surface27is relatively small.

The whole of the first region31may be located between the first side17and the second surface5in a front view of the first lateral surface27. Alternatively, at least a part of the first region31may be located between the first corner11and the second surface5. If at least the part of the first region31is located between the first corner11and the second surface5as described above, the first lateral surface27may be less likely to interfere with the workpiece during the cutting process, and the insert1may be stably fixable to the holder.

The first lateral surface27may be inclined or parallel to the central axis O1in a cross section that includes the central axis O1and intersects with the first lateral surface27.FIG.10may illustrate the cross section that includes the central axis O1and intersects with the first lateral surface27, and may illustrate a first imaginary straight line O1′ parallel to the central axis O1. If the first lateral surface27is parallel to the central axis O1(the first imaginary straight line O1′) in the above cross section, the insert1may be less susceptible to dislocation with respect to the holder, and the insert1may be more stably fixable to the holder.

The second lateral surface29may be located further outside than the second side19in the front view of the first surface3. In other words, the second lateral surface29may be located further away from the center of the first surface3than the second side19in the front view of the first surface3. If the second lateral surface29is located further outside than the second side19, the cutting edge9may be less likely to come into contact with the holder if the second lateral surface29is brought into contact with the holder in order to fix the insert1to the holder. Consequently, the holder and the cutting edge9may be less susceptible to damage.

The second lateral surface29may include a region located closer to the first lateral surface27as coming closer to the second surface5. Hereinafter, this region may be referred to as a second region35. The second region35may be located so as to include an end portion of the second lateral surface29which is located on a side of the first lateral surface27as illustrated inFIG.5.

At least a part of an outer peripheral edge of the second lateral surface29which is located on a side of the first lateral surface27may be included in the second region35. The part of the outer peripheral edge of the second lateral surface29which is included in the second region35may be located closer to the first lateral surface27as coming closer to the second surface5.

As in the non-limiting embodiment illustrated inFIG.1, the first curved surface33having the convex curved surface shape may be located between the first lateral surface27and the second lateral surface29. A boundary part C2between the second lateral surface29and the first curved surface33may be located closer to the first lateral surface27as coming closer to the second surface5as in the non-limiting embodiment illustrated inFIG.5. Specifically, the boundary part C2may extended obliquely in a direction from upper right to lower left as in the non-limiting embodiment illustrated inFIG.5.

The part of the outer peripheral edge of the second lateral surface29which is included in the second region35may be located closer to the first lateral surface27as coming closer to the second surface5. In other words, the part of the outer peripheral edge of the second lateral surface29which is included in the second region35may be located away from the first lateral surface27as coming closer to the first surface3. In this case, the second lateral surface29may be less likely to interfere with the workpiece if the first corner cutting edge25is used to carry out the cutting process of the workpiece. This may facilitate to obtain a smooth finish of a machined surface of the workpiece.

Additionally, the second lateral surface29may be less likely to interfere with the workpiece and may be less susceptible to wear. Consequently, the insert1may be stably fixable to the holder if the second lateral surface29is brought into contact with the holder in order to fix the insert1to the holder.

The whole of the second region35may be located between the second side19and the second surface5in a front view of the second lateral surface29. Alternatively, at least a part of the second region35may be located between the first corner11and the second surface5. If at least the part of the second region35is located between the first corner11and the second surface5as described above, the second lateral surface29may be less likely to interfere with the workpiece during the cutting process, and the insert1may be more stably fixable to the holder.

The second lateral surface29may be inclined or parallel to the central axis O1in a cross section that includes the central axis O1and intersects with the second lateral surface29.FIG.11may illustrate the cross section that includes the central axis O1and intersects with the second lateral surface29, and may illustrate a second imaginary straight line O1″ parallel to the central axis O1. If the second lateral surface29is parallel to the central axis O1(the second imaginary straight line O1″) in the above cross section, the insert1may be less susceptible to dislocation with respect to the holder, and the insert1may be more stably fixable to the holder.

In cases where the lateral surface7includes the first lateral surface27and the second lateral surface29, a width of the first lateral surface27in a direction parallel to the central axis O1may be a first width W1, and a width of the second lateral surface29in the direction parallel to the central axis O1may be a second width W2. For example, the second width W2may be larger than the first width W1.

If the first cutting edge21is used as a bottom cutting edge and the second cutting edge23is used as an outer peripheral cutting edge in the cutting process, the second cutting edge23may be susceptible to relatively large cutting load. If the second width W2is larger than the first width W1, the second cutting edge23may have enhanced strength. This may lead to enhanced durability of the insert1.

The lateral surface7may further include a first connection surface37and a second connection surface39. The first connection surface37may be located in a region in the lateral surface7which is located along the first side17, and may connect to the first side17as illustrated inFIG.4. The first connection surface37may be located between the first side17and the first lateral surface27in the non-limiting embodiment illustrated inFIG.4.

The second connection surface39may be located in a region in the lateral surface7which is located along the second side19, and may connect to the second side19as illustrated inFIG.5. The second connection surface39may be located between the second side19and the second lateral surface29in the non-limiting embodiment illustrated inFIG.5.

The first connection surface37may be inclined or parallel to the central axis O1in the cross section including the central axis O1. The first connection surface37may be parallel to the first imaginary straight line O1′ inFIG.10. If the first connection surface37is parallel to the central axis O1(the first imaginary straight line O1′) in the above cross section, the first lateral surface27may be much less likely to interfere with the workpiece. Consequently, a machined surface of the workpiece may tend to have a smoother finish.

If the first connection surface37is parallel to the central axis O1, the first cutting edge21may have a sharp blade tip. Hence, in the case of using the first cutting edge21as a bottom cutting edge, the machined surface of the workpiece particularly may tend to have a smoother finish.

A width of the first connection surface37in the direction parallel to the central axis O1may become larger as coming closer to the first corner11in the front view of the first lateral surface27. If the first cutting edge21is used to carry out the cutting process, a part of the first lateral surface27which is located closer to the second lateral surface29may tend to come into contact with the workpiece.

If the width of the first connection surface37becomes larger as described above, even the part of the first lateral surface27which tends to come into contact with the workpiece may be less likely to interfere with the workpiece. This may lead to a smoother finish of the machined surface of the workpiece.

The second connection surface39may be inclined or parallel to the central axis O1in the cross section including the central axis O1. For example, the second connection surface39may include a part inclined so as to be located further away from the central axis O1(the second imaginary straight line O1″) as going away from the second side19in the above cross section.

If the second connection surface39is inclined as described above, the blade tip of the second cutting edge23may have a large thickness and enhanced strength. The insert1may have enhanced durability because of the enhanced strength of the second cutting edge23that is susceptible to a relatively large cutting load.

The width of the second connection surface39in the direction parallel to the central axis O1may become larger as coming closer to the first corner11in the front view of the second lateral surface29. If the second cutting edge23is used to carry out the cutting process, a part of the second lateral surface29which is located closer to the first lateral surface27may be more likely to come into contact with the workpiece.

If the width of the second connection surface39becomes larger as described above, even the part of the second lateral surface29which tends to come into contact with the workpiece may be less likely to interfere with the workpiece. This may lead to a smoother finish of the machined surface of the workpiece.

The first surface3may further include a fourth corner41, a third side43and a fourth side45. The fourth corner41may be located adjacent to the second corner13and the third corner15. The third side43may be located between the second corner13and the fourth corner41. The fourth side45may be located between the third corner15and the fourth corner41.

The other of the short sides of the first surface3having the rectangular shape may be the fourth side45in the non-limiting embodiment illustrated inFIG.2. The other of the long sides of the first surface3having the rectangular shape may be the third side43in the non-limiting embodiment illustrated inFIG.2. Similarly to the first corner11, the second corner13and the third corner15, the fourth corner41is not limited to a strict corner.

The cutting edge9may include a third cutting edge47, a fourth cutting edge49and a second corner cutting edge51as illustrated inFIG.2. The third cutting edge47may be located on the third side43. The third cutting edge47may be usable as an outer peripheral cutting edge. The fourth cutting edge49may be located on the fourth side45. For example, if the insert1of the present embodiment is used to carry out the cutting process of the workpiece, the fourth cutting edge49may be usable as a bottom cutting edge located along the machined surface of the workpiece.

In cases where the fourth cutting edge49is used as the bottom cutting edge and the third cutting edge47is used as the outer peripheral cutting edge as described above, the third cutting edge47may mainly contribute to the cutting process. The third cutting edge47may therefore be called the main cutting edge9in some cases. The second corner cutting edge51may be located at the fourth corner41. The second corner cutting edge51may be located over the whole of the fourth corner41as illustrated inFIG.2.

The lateral surface7may further include a third lateral surface53and a fourth lateral surface55as illustrated inFIGS.6and7. At least a part of the third lateral surface53may be located between the third side43and the second surface5. The third lateral surface53may have a planar shape. At least a part of the fourth lateral surface55may be located between the fourth side45and the second surface5. The fourth lateral surface55may have a planar shape.

The third lateral surface53and the fourth lateral surface55may be used as a surface brought into contact with the holder if fixing the insert1to the holder. The insert1may be stably fixable to the holder because the third lateral surface53and the fourth lateral surface55are flat.

For example, if the first cutting edge21, the second cutting edge23and the first corner cutting edge25may be used in the cutting process of the workpiece, the third lateral surface53and the fourth lateral surface55may be brought into contact with the holder. If the third cutting edge47, the fourth cutting edge49and the second corner cutting edge51are used in the cutting process of the workpiece, the first lateral surface27and the second lateral surface29may be brought into contact with the holder.

The fourth lateral surface55may be located further outside than the fourth side45in the front view of the first surface3. In other words, the fourth lateral surface55may be located further away from the center of the first surface3than the fourth side45in the front view of the first surface3. If the fourth lateral surface55is located further outside than the fourth side45, the cutting edge9may be less likely to come into contact with the holder if the fourth lateral surface55is brought into contact with the holder in order to fix the insert1to the holder. The holder and the cutting edge9may therefore be less susceptible to damage.

The first lateral surface27may include a region located further away from the third lateral surface53as coming closer to the second surface5. Hereinafter, this region may be referred to as a third region57. The third region57may be located so as to include an end portion of the first lateral surface27which is located on a side of the third lateral surface53as illustrated inFIG.4.

At least a part of an outer peripheral edge of the first lateral surface27which is located on a side of the third lateral surface53may be included in the third region57. The part of the outer peripheral edge of the first lateral surface27which is included in the third region57may be located further away from the third lateral surface53as coming closer to the second surface5.

As illustrated inFIG.1, a second curved surface59having a convex curved surface shape may be located between the first lateral surface27and the third lateral surface53. The second curved surface59may be located between the second corner13and the second surface5as in the non-limiting embodiment illustrated inFIG.1. A boundary part C3between the first lateral surface27and the second curved surface59may be located further away from the third lateral surface53as coming closer to the second surface5as in the non-limiting embodiment illustrated inFIG.4. Specifically, the boundary part C3may be extended obliquely in a direction from upper left to lower right as in the non-limiting embodiment illustrated inFIG.4.

The part of the first lateral surface27which is included in the third region57may be located further away from the third lateral surface53as coming closer to the second surface5. In other words, the part of the outer peripheral edge of the first lateral surface27which is included in the third region57may be located closer to the third lateral surface53as coming closer to the first surface3.

The insert1may tend to be stably restricted by the holder even if a large thrust force (force in a direction from the fourth corner41toward the second corner13) is applied to the second corner cutting edge51in the cutting process of the workpiece by using the second corner cutting edge51.

The lateral surface7may further include a third connection surface61. The third connection surface61may be located in a region in the lateral surface7which is located along the first corner11, and may connect to the first corner11as illustrated inFIG.1. The third connection surface61may be located between the first corner11and the first curved surface33in the non-limiting embodiment illustrated inFIG.1.

The third connection surface61may be inclined or parallel to the central axis O1in the cross section including the central axis O1.FIG.12may correspond to the cross section including the central axis O1and may illustrate a third imaginary straight line O1′″ parallel to the central axis O1. For example, the third connection surface61may be inclined so as to be located away from the central axis O1(the third imaginary straight line O1′″) as going away from the first corner11in the above cross section.

If the third connection surface61is inclined as described above, a blade tip of the first corner cutting edge25may have a large thickness and enhanced strength. The insert1may have enhanced durability because of the enhanced strength of the first corner cutting edge25that is susceptible to a relatively large cutting load.

In cases where the lateral surface7includes the third connection surface61, the third connection surface61may include a fourth region63. The fourth region63may have a larger inclination angle relative to the central axis O1as going away from the first side17. If the third connection surface61includes the fourth region63, strength of the second cutting edge23can be enhanced while sharpening the blade tip of the first cutting edge21.

The first surface3may include a land surface65and an inclined surface67as in the non-limiting embodiment illustrated inFIG.2. The land surface65may be located along the first side17, the second side19and the first corner11. This may be rephrased that the land surface65is located along the first cutting edge21, the second cutting edge23and the first corner cutting edge25in a non-limiting embodiment illustrated inFIG.9. The cutting edge9may have enhanced durability if the first surface3includes the land surface65.

The inclined surface67may be located along the land surface65. The inclined surface67may be located further inside the first surface3than the land surface65in the non-limiting embodiment illustrated inFIG.2. The inclined surface67may be located closer to the reference plane S1as going away from the land surface65. The inclined surface67in the first surface3may be the rake surface region as described above.

If the first surface3includes the inclined surface67that is servable as a rake surface, it may be easy to control a flow direction of chips generated by the cutting edge9during the cutting process, thus leading to enhanced chip discharge performance. An inclination angle of the inclined surface67may be larger than an inclination angle of the land surface65. As used herein, the term “inclination angle of each of the land surface65and the inclined surface67” may denote an angle relative to the reference plane S1.

The insert1may include a through hole69that opens into regions located on opposite sides of the lateral surface7, specifically the second lateral surface29and the third lateral surface53as in the non-limiting embodiment illustrated inFIGS.5and7. A central axis O1of the through hole69may be inclined or orthogonal to the central axis O1of the insert1.

The through hole69may be usable to insert, for example, a screw if fixing the insert1to the holder. Instead of the screw, for example, a clamping member may be used to fix the insert1to the holder.

Although the through hole69opens into the regions located on the opposite sides of the lateral surface7in the non-limiting embodiment illustrated inFIG.1, it is not intended to limit the through hole69to the above configuration. For example, the through hole69may be formed from the center of the first surface3toward the center of the second surface5.

For example, cemented carbide and cermet may be usable as a material of the insert1. Examples of composition of the cemented carbide may include WC—Co, WC—TiC—Co and WC—TiC—TaC—Co, in which WC, TiC and TaC may be hard particles, and Co may be a binding phase.

The cermet may be a sintered composite material obtainable by compositing metal into a ceramic component. Examples of the cermet may include titanium compounds composed mainly of titanium carbide (TiC) or titanium nitride (TiN). However, it is not intended to limit the material of the insert1to the above composition.

A surface of the insert1may be coated with a coating film by using chemical vapor deposition (CVD) method or physical vapor deposition (PVD) method. Examples of composition of the coating film may include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN) and alumina (Al2O3).

<Cutting Tools>

A cutting tool101in a non-limiting embodiment is described below with reference toFIGS.13and14.FIGS.13and14may illustrate a state where the insert illustrated inFIG.1is attached to a pocket105of a holder103by a screw107. A rotation axis O2of the cutting tool101may be indicated by a two-dot chain line inFIG.13or the like.

The cutting tool101in the present embodiment may be used for a milling process. The cutting tool101may include the holder103and the insert as illustrated inFIG.13. The holder103may have a columnar shape extended from a first end to a second end along a rotation axis O2. The holder103may include a pocket105located on a side of the first end. The insert may be located in the pocket105.

The holder103may include only one pocket105, or alternatively, a plurality of pockets105as in a non-limiting embodiment illustrated inFIG.13. If the holder103includes the pockets105, the cutting tool101may include a plurality of inserts, and the inserts may be located one by one in the pockets105.

The pocket105may open into an outer peripheral surface of the holder103and an end surface on a side of the first end. In cases where the holder103includes the pockets105, these pockets105may be located at equal intervals or unequal intervals around the rotation axis O2. As apparent from, for example, the fact that the holder103includes the pockets105, the holder103may not be a strict columnar shape.

The insert1may be attached to the pocket105so that at least a part of the cutting edge is protruded from the holder103. Specifically, the insert1of the present embodiment may be attached to the holder103so that the second cutting edge is located more outside than the outer peripheral surface in the holder, and the first cutting edge is protruded from the holder103toward a workpiece.

At least a flat surface region in the second surface and the lateral surface in the insert may be in contact with the holder103in the cutting tool101of the present embodiment.

The insert may be attached to the pocket105by a screw107in the present embodiment. Specifically, the insert may be attached to the holder103by inserting the screw107into a screw hole of the insert, and by inserting a front end of the screw107into a screw hole formed in the pocket105so as to fix the screw107to the screw hole.

For example, steel or cast iron may be used as a material of the holder103. Of these materials, the use of steel may particularly contribute to enhancing toughness of the holder103.

<Method for Manufacturing Machined Product>

A method for manufacturing a machined product in a non-limiting aspect of the present disclosure may be described below with reference toFIGS.15to17.FIGS.15to17may illustrate a method for manufacturing a machined product in a cutting process using the above cutting tool. The rotation axis O2of the cutting tool101may be indicated by a two-dot chain line inFIGS.15to17. The machined product203may be manufacturable by carrying out the cutting process of the workpiece201.

The method for manufacturing the machined product may include the following steps:(1) rotating the cutting tool101represented by the foregoing non-limiting embodiment;(2) bringing the cutting tool101being rotated into contact with the workpiece201; and(3) moving the cutting tool101away from the workpiece201.

Specifically, firstly, the cutting tool101may be relatively brought near the workpiece201while rotating the cutting tool101in Y direction around the rotation axis O2as illustrated inFIG.15. The workpiece201may be then cut out by bringing the cutting edge of the cutting tool101into contact with the workpiece201as illustrated inFIG.16. Thereafter, the cutting tool101may be relatively moved away from the workpiece201as illustrated inFIG.17.

The workpiece201may be fixed and the cutting tool101may be brought near the workpiece201. The workpiece201may be fixed and the cutting tool101may be rotated around the rotation axis O2as in a non-limiting embodiment illustrated inFIGS.15to17. The workpiece201may be fixed and the cutting tool101may be moved away as in the non-limiting embodiment illustrated inFIG.17.

In the non-limiting embodiment illustrated inFIGS.15to17, the workpiece201may be fixed and the cutting tool101may be moved in each of the steps. However, it is not intended to limit to this embodiment.

For example, the workpiece201may be brought near the cutting tool101in the step (1). Similarly, the workpiece201may be moved away from the cutting tool101in the step (3). If it is desired to continue the cutting process, the step of bringing the cutting edge of the insert into contact with different portions of the workpiece201may be repeated while keeping the cutting tool101rotated.

Representative examples of material of the workpiece201may include carbon steel, alloy steel, stainless steel, cast iron and nonferrous metals.