Claims:

1. A square, indexable, double-sided cutting insert (10, 10’), comprising:
a first surface (12);
a second surface (14) opposite the first surface (12);
a plurality of side surfaces (16) connecting the first surface (12) and the second surface (14);
a cutting edge (17) formed at an intersection between the plurality of side surfaces (16) and the first surface (12) and at an intersection between the plurality of side surfaces (16) and the second surface (14), each cutting edge (17) comprising a primary cutting edge (18) and a secondary wiper edge (19);
a rake face (30) extending downwardly from each primary cutting edge (18) and each secondary wiper edge (19) to a planar central region (26) of the cutting insert (10, 10’); and
a plurality of rounded corners (20) connecting the first and second surfaces (12, 14) and the plurality of side surfaces (16),
characterized in that:
each primary cutting edge (18) has a concave edge profile for producing a 90º wall on a workpiece (200), and
each secondary wiper edge (19) has a convex edge profile for producing a smooth finish on the workpiece (200).

2. The cutting insert (10, 10’) of Claim 1, wherein the rounded corners (20) connecting the same side surface (16) to adjacent side surfaces (16) are mirror symmetric with respect to each other about the horizontal axis.

3. The cutting insert (10) of Claim 1, wherein each secondary wiper edge (19) has a highest point, P, in elevation located on a horizontal axis passing through a central, longitudinal axis (24) of the cutting insert (10).

4. The cutting insert (10) of Claim 1, wherein each primary cutting edge (18) has a length, LC, that constitutes 5-25% of a total length, LT, of each cutting edge (17), and wherein each secondary wiper edge (19) has a length, LW, that constitutes 75-95% of the total length, LT, of the cutting edge (17).

5. The cutting insert (10’) of Claim 1, wherein each primary cutting edge (18) has a length, LC, that constitutes 35-60% of a total length, LT, of each cutting edge (17), and each secondary wiper edge (19) has a length, LW, that constitutes 40-65% of the total length, LT, of the cutting edge (17).

6. The cutting insert (10, 10’) of Claim 1, wherein each rounded corner (20) is formed with a radius in the range between 0.4 mm (0.02 inches) and 3.2 mm (0.13 inches).

7. The cutting insert (10, 10’) of Claim 1, further comprising a countersunk bore (22) extending entirely between the first and second surfaces (12, 14), and is centrally located with respect to a central, longitudinal axis (24) of the cutting insert (10, 10’).

8. The cutting insert (10, 10’) of Claim 1, wherein the planar central region (26) is substantially square in shape.

9. The cutting insert (10, 10’) of Claim 1, wherein the second surface (14) is identical to the first surface (12), wherein each side surface (16) is identical to each other, and wherein each rounded corner (20) is identical to each other.

10. A square, indexable, double-sided cutting insert (10, 10’), comprising:
a first surface (12);
a second surface (14) opposite and identical to the first surface (12);
four identical side surfaces (16) connecting the first surface (12) and the second surface (14);
eight identical cutting edges (17) formed at an intersection between the plurality of side surfaces (16) and the first surface (12) and at an intersection between the plurality of side surfaces (16) and the second surface (14), each cutting edge (17) comprising a primary cutting edge (18) and a secondary wiper edge (19); and
four identical rounded corners (20) connecting the first and second surfaces (12, 14) and the plurality of side surfaces (16),
characterized in that:
each primary cutting edge (18) has a concave edge profile for producing a 90º wall on a workpiece (200), and
each secondary wiper edge (19) has a convex edge profile for producing a smooth finish on the workpiece (200).

11. The cutting insert (10, 10’) of Claim 10, wherein one rounded corner (20) connecting a first end (16a) of each side surface (16) has a concave edge shape, and wherein another rounded corner (20) at a second opposite end (16b) of each side surface (16) has a convex edge shape.

12. The cutting insert (10, 10’) of Claim 10, further comprising a rake face (30) extending downwardly from each primary cutting edge (18) and each secondary wiper edge (19) to a planar central region (26).

13. The cutting insert (10, 10’) of Claim 10, further comprising a countersunk bore (22) extending entirely between the first and second surfaces (12, 14), and is centrally located with respect to a central, longitudinal axis (24) of the cutting insert (10, 10’).

14. A cutting tool (100), comprising:
a tool body (102) having a plurality of pockets (116) for mounting a square, indexable, double-sided cutting insert (10), the cutting insert comprising:
a first surface (12);
a second surface (14) opposite the first surface (12);
a plurality of side surfaces (16) connecting the first surface (12) and the second surface (14);
a first plurality of cutting edges (17) formed at an intersection between the plurality of side surfaces (16) and the first surface (12), each cutting edge (17) of the first plurality of cutting edges (17) comprising a primary cutting edge (18) and a secondary wiper edge (19);
a second plurality of cutting edges (17) formed at an intersection between the plurality of side surfaces (16) and the second surface (14), each cutting edge (17) of the second plurality of cutting edges (17) comprising a primary cutting edge (18) and a secondary wiper edge (19);
a rake face (30) extending downwardly from each primary cutting edge (18) and each secondary wiper edge (19) to a planar central region (26); and
a plurality of rounded corners (20) connecting the first and second surfaces (12, 14) and the plurality of side surfaces (16),
characterized in that:
each primary cutting edge (18) has a concave edge profile for producing a 90º wall on a workpiece (200), and
each secondary wiper edge (19) has a convex edge profile for producing a smooth finish on the workpiece (200).

15. The cutting tool (100) of Claim 14, wherein one rounded corner (20) connecting a first end (16a) of each side surface (16) of the cutting insert (10, 10’) has a concave edge shape, and wherein another rounded corner (20) at a second opposite end (16b) of each side surface (16) of the cutting insert (10, 10’) has a convex edge shape.

16. The cutting tool (100) of Claim 14, wherein the cutting insert (10, 10’) further comprises a countersunk bore (22) extending entirely between the first and second surfaces (12, 14), and is centrally located with respect to a central, longitudinal axis (24) of the cutting insert (10, 10’).

, Description:FIELD OF THE DISCLOSURE
[0001] The invention pertains to the field of indexable cutting inserts. More particularly, the invention pertains to a square cutting insert with eight cutting edges and eight wiper edges.

BACKGROUND OF THE DISCLOSURE
[0002] Modern high-performance cutting tools use replaceable and typically indexable inserts owing to the high cutting speeds and feeds supported by the superior insert materials. Common materials for inserts include tungsten carbide, polycrystalline diamond and cubic boron nitride.
[0001] Indexable inserts use a symmetrical polygonal shape, such that when the first cutting edge is blunt, they can be rotated or flipped over, presenting a fresh cutting edge which is accurately located at the same geometrical position. Geometrical repeatability saves time in manufacturing by allowing periodical renewal of the cutting edge without the need for tool grinding, setup changes, or entering of new values into a CNC program.
[0002] The number of cutting edges is directly related to the cost per edge of the cutting insert. The more cutting edges that are available, the more the cutting insert has value.
[0003] Currently, square, indexable cutting inserts for machining a 90º shoulder in a workpiece are single-sided cutting inserts with at most four cutting edges and four wiper edges. Thus, it is desirable to provide a square, indexable, double-sided cutting insert with more than four cutting edges and four wiper edges for machining a 90º shoulder and a high-quality surface finish on the workpiece, thereby reducing machining costs.

SUMMARY OF THE DISCLOSURE
[0004] A problem of maximizing the number of primary cutting edges and wiper cutting edges in a square cutting insert can be solved by providing a double-sided, square cutting insert with a plurality of cutting edges formed at the intersection between both the first (or top) and the second (or bottom) surfaces and each side surface for a total of eight cutting edges, wherein each cutting edge comprises a primary cutting edge with a concave profile shape for providing a perfect 90º wall, and a secondary wiper edge with a convex profile shape for providing a perfect wiper radius to produce a smooth surface on the workpiece.
[0005] In one aspect, an indexable, double-sided cutting insert comprises a first surface; a second surface opposite the first surface; a plurality of side surfaces connecting the first surface and the second surface. A cutting edge is formed at an intersection between the plurality of side surfaces and the first surface and at an intersection between the plurality of side surfaces and the second surface, each cutting edge comprising a primary cutting edge and a secondary wiper edge. A rake face extends downwardly from each primary cutting edge and each secondary wiper edge to a planar central region. A plurality of rounded corners connects the first and second surfaces and the plurality of side surfaces. Each primary cutting edge has a concave edge profile for producing a 90º wall on a workpiece, and each secondary wiper edge has a convex edge profile for producing a smooth finish on the workpiece.
[0006] In another aspect, a square, indexable, double-sided cutting insert comprises a first surface; a second surface opposite and identical to the first surface; four identical side surfaces connecting the first surface and the second surface; eight identical cutting edges formed at an intersection between the plurality of side surfaces and the first surface and at an intersection between the plurality of side surfaces and the second surface, each cutting edge comprising a primary cutting edge and a secondary wiper edge; and four identical rounded corners connecting the first and second surfaces and the plurality of side surfaces. Each primary cutting edge has a concave edge profile for producing a 90º wall on a workpiece, and each secondary wiper edge has a convex edge profile for producing a smooth finish on the workpiece.
[0007] In yet another aspect, a cutting tool comprises a tool body having a plurality of pockets for mounting a square, indexable, double-sided cutting insert. The cutting insert comprising a first surface; a second surface opposite the first surface; a plurality of side surfaces connecting the first surface and the second surface. A first plurality of cutting edges is formed at an intersection between the plurality of side surfaces and the first surface, each cutting edge of the first plurality of cutting edges comprising a primary cutting edge and a secondary wiper edge. A second plurality of cutting edges is formed at an intersection between the plurality of side surfaces and the second surface, each cutting edge of the second plurality of cutting edges comprising a primary cutting edge and a secondary wiper edge. A rake face extends downwardly from each primary cutting edge and each secondary wiper edge to a planar central region. A plurality of rounded corners connects the first and second surfaces and the plurality of side surfaces. Each primary cutting edge has a concave edge profile for producing a 90º wall on a workpiece, and each secondary wiper edge has a convex edge profile for producing a smooth finish on the workpiece.

BRIEF DESCRIPTION OF THE DRAWINGS
[0008] While various embodiments are illustrated, the particular embodiments shown should not be construed to limit the claims. It is anticipated that various changes and modifications may be made without departing from the scope of this disclosure.
[0009] FIG. 1 is an isometric view of a first surface of a square, indexable, double-sided cutting insert according to an embodiment;
[00010] FIG. 2 is a top view of the cutting insert of FIG. 1;
[00011] FIG. 3 is a side view of the cutting insert of FIG. 1;
[00012] FIG. 4 is a front view of a cutting tool, such as a milling cutter, with the cutting insert of FIG. 1 mounted in the pockets of the cutting tool;
[00013] FIG. 5 is an enlarged view of the cutting insert of FIG. 1 mounted in the pocket of the cutting tool; and
[00014] FIG. 6 is an isometric view of a first surface of a square, indexable, double-sided cutting insert according to an alternate embodiment.

DETAILED DESCRIPTION
[00015] Referring now to FIGS. 1-3, a cutting insert 10 is generally shown according to an embodiment. In general, the cutting insert 10 comprises a square, indexable, double-sided cutting insert. Although other geometric shapes are possible, the cutting insert 10 of the illustrated embodiment is of a generally symmetrical (i.e., mirror symmetry) about all three axes (i.e., the x, y and z-axes) and includes four main cutting edges and four wiper edges at the intersection between the top and bottom surfaces and each side surface for a total of eight primary cutting edges and eight secondary wiper edges. However, it will be appreciated that the disclosure can be practiced with any multiple number of primary cutting edges and secondary wiper edges. It will also be appreciated that the principles of the disclosure can be practiced with any polygonal-shaped cutting insert, so long as the cutting insert is symmetrical about all three axes.
[00016] Directional phrases used herein, such as, for example, left, right, front, back, top, bottom and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. Identical parts are provided with the same reference number in all drawings.
[00017] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.
[00018] Throughout the text and the claims, use of the word "about" in relation to a range of values (e.g., "about 22 to 35 wt %") is intended to modify both the high and low values recited, and reflects the penumbra of variation associated with measurement, significant figures, and interchangeability, all as understood by a person having ordinary skill in the art to which this disclosure pertains.
[00019] For purposes of this specification (other than in the operating examples), unless otherwise indicated, all numbers expressing quantities and ranges of ingredients, process conditions, etc., are to be understood as modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired results sought to be obtained by embodiments. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Further, as used in this specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural referents, unless expressly and unequivocally limited to one referent.
[00020] Notwithstanding that the numerical ranges and parameters setting forth the broad scope are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements including that found in the measuring instrument. Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10, i.e., a range having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.
[00021] In the following specification and the claims, a number of terms are referenced that have the following meanings.
[00022] The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[00023] “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
[00024] As used herein, “concave” is defined as curved, like a segment of the interior of a circle or hollow sphere; hollow and curved.
[00025] As used herein, “convex” is defined as having a surface that is curved or rounded outward.
[00026] As used herein, “planar” is defined as flat or level.
[00027] As used herein, “flank” is defined as the side of anything, such as a three-dimensional object.
[00028] As used herein, “wiper edge drop” is defined as the vertical distance measured from the highest point, P, in elevation to the low point on the curvature formed by the wiper edge.
[00029] Referring now to FIGS. 1-3, the cutting insert 10 includes a first surface 12, a second surface 14 opposite the first surface 12 and a plurality of flank or side surfaces 16 connecting the first surface 12 and the second surface 14. Although not shown in FIG. 1, the second surface 14 is identical to the first surface 12, and the flank surfaces 16 are identical to each other. Thus, the cutting insert 10 is symmetric about all three axes (x-, y-, z-), and therefore only the first surface 12 will be described in detail herein for brevity. However, it will be appreciated that any discussion of the first surface 12 applies to the second surface 14, and any discussion of the flank surface 16 applies to the other flank surfaces 16.
[00030] In general, each side surface 16 (only two are shown in FIG. 1) is substantially perpendicular to both the first and second surfaces 12, 14. In other words, the first and second surfaces 12, 14 are substantially parallel to each other and perpendicular to the side surfaces 16. That is, the side surfaces 16 have a facet clearance angle of zero degrees. Thus, both the first and second surfaces 12, 14 of the cutting insert 10 can be presented to a workpiece 200 (FIG. 5). In the illustrated embodiment, the cutting insert 10 has a total of four identical side surfaces 16. Thus, only one side surface 16 will be described herein for brevity, and it will be appreciated that any description herein of one of the side surfaces 16 applies to all the side surfaces 16.
[00031] A cutting edge 17 is formed at the intersection between the first surface 12 and each side surface 16 for a total of four cutting edges 17. In addition, a cutting edge 17 is formed at the intersection between the second surface 14 and each side surface 16 for a total of four additional cutting edges 17 (i.e. a total of eight cutting edges 17 for the cutting insert 10). Each cutting edge 17 is identical to each other. Thus, only one cutting edge 17 will be described herein for brevity, and it will be appreciated that any description herein of one cutting edge 17 applies to all the cutting edges 17.
[00032] Referring now to FIG. 3, each cutting edge 17 comprises a main or primary cutting edge 18 and a secondary wiper edge 19. Thus, the cutting insert 10 has a total of eight main cutting edges 18 and wiper edges 19. The primary cutting edge 18 has a length, LC, that constitutes about 5-25% of a total length, LT, of the cutting edge 17. In addition, the wiper edge 19 has a length, LW, that constitutes about 75-95% of the total length, LT, of the cutting edge 17.
[00033] Referring now to FIGS. 2 and 3, the secondary wiper edge 19 has a highest point, P, in elevation that is located on the horizontal x- and y-axes passing through a central, longitudinal axis 24 of the cutting insert 10. However, it will be appreciated that the invention is not limited by the location of the highest point, P, in elevation of the secondary wiper edge 19, and that the highest point, P, in elevation can be located at any desirable location along the secondary wiper edge 19 to achieve a desired wiper edge drop.
[00034] A rounded corner 20 connects adjacent side surfaces 16 and also connects the first surface 12 and the second surface 14. As best shown in FIGS. 1 and 3, one rounded corner 20 connecting a first end 16a of a side surface 16 has a concave edge shape, whereas a different rounded corner 20 at the second opposite end 16b of the same side surface 16 has a convex edge shape. In other words, the rounded corners 20 connecting the same side surface 16 to adjacent side surfaces 16 are mirror symmetric with respect to each other about the horizontal axis (i.e. x-axis). Preferably, each rounded corner 20 is formed with a radius in the range between approximately 0.4 mm (0.02 inches) and approximately 3.2 mm (0.13 inches). For example, the rounded corner 20 may have a radius of about 0.8 mm (0.031 inches). Because each rounded corner 20 is substantially identical to each other, only one rounded corner 20 is discussed herein for brevity, and it will be appreciated that any description herein of one rounded corner 20 applies to all rounded corners 20.
[00035] The cutting insert 10 also includes a countersunk bore 22 extending entirely between the first and second surfaces 12, 14, and is centrally located with respect to the central, longitudinal axis 24 (i.e., the z-axis). As stated earlier, the cutting insert is symmetric about all three axes (x-, y- and z-axes). As a result, the cutting insert 10 comprises an indexable, double-sided polygonal cutting insert in which all eight main cutting edges 18 and all eight wiper edges 19 are identical to each other and can separately be used in a machining operation.
[00036] The first surface 12 (and the second surface 14) has a topography that includes a substantially planar central region 26 surrounding the countersunk bore 22. The central region 26 extends from the countersunk bore 22 and terminates in a substantially square-shaped boundary 28. As mentioned earlier, each side surface 16 is substantially perpendicular to both the first and second surfaces 12, 14. More specifically, the substantially planar central region 26 of the first and second surfaces 12, 14 are substantially parallel to each other and perpendicular to the side surfaces 16.
[00037] The first surface 12 also includes a rake face 30 extending radially inward from each cutting edge 18 to the irregular-shaped boundary 28. As shown in FIGS. 1 and 2, each rake face 30 slopes upwardly from the central region 26 to the main cutting edge 18 and the wiper edge 19 (i.e., each rake face 30 slopes downwardly from the main cutting edge 18 and the wiper edge 19 to the boundary 28). As a result, each rake face 30 is higher in elevation than the central region 26.
[00038] In one aspect, each cutting edge 17 has a wavy or curved cutting edge profile. Specifically, as shown in FIG. 3, for example, each main cutting edge 18 has a concave edge profile for rough cutting a workpiece 200 (FIGS. 4 and 5), whereas each wiper edge 19 has a convex edge profile for finish cutting the workpiece 200. As mentioned above, the cutting insert 10 has a total of eight cutting edges 17 (i.e., eight main cutting edges 18 and eight wiper edges 19) because the substantially square cutting insert 10 has mirror symmetry about all three axes (i.e., x-, y- and z-axes). In another aspect, the concave edge profile of the main cutting edge 18 enables the cutting insert 10 to produce a perfect 90º wall, and the convex edge profile of the wiper edge 19 enables the cutting insert 10 to produce a perfect wiper radius and superior finish during cutting operations (See FIGS. 4 and 5).
[00039] Referring now to FIGS. 4 and 5, a cutting tool 100, for example, a milling cutter, is shown according to an embodiment of the disclosure. The milling cutter 100 comprises a tool body 112 including a cutting end 114 with a plurality of circumferentially spaced pockets 116, and a mounting end 118 opposite the cutting end 114. The tool body 112 is designed to be rotatably driven about a central longitudinal axis 113. In the illustrated embodiment, the milling cutter 100 is commonly known as a right-hand milling cutter and includes a plurality of insert-receiving pockets 116. However, it will be appreciated that the invention is not limited by the number of insert-receiving pockets 116, and that the invention can be practiced with any desirable number of pockets that provide the desired cutting capabilities. Each of the pockets 116 are capable of receiving the cutting insert 10, which is securely held in the insert-receiving pocket 116 by means of a mounting screw 119.
[00040] Two side surfaces 16 of the cutting insert 10 and one of the first and second surfaces 12, 14 contact the insert-receiving pocket 116 to make three-point contact with the pocket 116 when the cutting insert 10 is properly mounted in the pocket 116 during cutting operations. It will be appreciated that each of the main cutting edges 18 and wiper edges 19 can be indexed into an active position and effectively utilized in the milling cutter 100, as shown in FIGS. 4 and 5. It will be appreciated that the number of cutting edges 17 (i.e., main cutting edges 18 and wiper edges 19), and the number of times that the cutting insert 10 can be indexed depends on the geometric shape of the cutting insert 10. In general, the number of times the cutting insert 10 can be indexed is equal to the total number of cutting edges 17. Thus, the double-sided cutting insert 10 can be indexed eight times, unlike conventional single-sided rectangular or square cutting inserts that can be indexed at most only four times because of the fewer total number of cutting edges.
[00041] Referring to FIG. 5, the cutting insert 10 can be mounted in a respective pocket 116 of the milling cutter 100 such that the desired number of cutting edges 17 contact the workpiece 200. In one embodiment, the main cutting edge 18 of two of the cutting edges 17 produces a “perfect” 90º wall on the workpiece 200, while the wiper edge 19 of the each cutting edge 17 forms a “perfect” wiper radius that produces a smooth surface on the workpiece 200.
[00042] Measurements indicate that the indexable, double-sided cutting insert 10 of the disclosure provides superior performance, as compared to a conventional single-sided cutting insert, while doubling the number of indexable cutting edges. For example, measurements were performed on a cutting insert 10 designed with a wiper edge length, LW, of about 6.12 mm (0.241 inches) and a maximum axial depth-of-cut, DOC, of about 1.18 mm. Such measurements indicated that the cutting insert 10 produces a bottom clearance, BC, of about 0.056 mm. Further, the main cutting edge 18 of each cutting edge 17 of the cutting insert 10 produces a wall angle, WA, of about 90.07º, or what may be known in the art as a “perfect” 90º wall, as shown in FIG. 5.
[00043] It should be appreciated that the disclosure is not limited by the length, LW, of the wiper edge 19, and that the invention can be practiced with any desirable length, LW, of the wiper edge 19, depending on the desired maximum axial depth-of-cut, DOC. As mentioned above, the cutting insert 10 is designed for a maximum axial depth-of-cut of about 1.18 mm.
[00044] Referring now to FIG. 6, an indexable, double-sided, square cutting insert 10’ is shown according to an alternate embodiment of the disclosure. Similar to the cutting insert 10, the cutting insert 10’ of the illustrated embodiment is of a generally symmetrical about all three axes (i.e., the x, y and z-axes) and includes four main cutting edges and four wiper edges at the intersection between the top and bottom surfaces and each side surface for a total of eight main cutting edges and eight wiper edges. The cutting insert 10’ is substantially identical to the cutting insert 10, except that the cutting insert 10’ is designed with a higher depth-of-cut, DOC, and a reduced length, LW, of the secondary wiper edge 19. In this embodiment, the primary cutting edge 18 of the cutting insert 10’ has a length, LC, that constitutes about 35-60% of a total length, LT, of the cutting edge 17, and the secondary wiper edge 19 has a length, LW, that constitutes about 40-65% of the total length, LT, of the cutting edge 17.
[00045] As described above, the double-sided, indexable, square cutting insert 10, 10’ of the disclosure provides a total of eight cutting edges 17. Each cutting edge 17 has a primary cutting edge 18 with a convex edge profile for forming a “perfect” 90º wall on the workpiece 200, and a secondary wiper edge 19 with a concave edge profile forming a “perfect” wiper radius for producing a smooth finish on the workpiece 200.
[00046] Having described presently preferred embodiments the invention may be otherwise embodied within the scope of the appended claims.

PARTS LIST
10 cutting insert
12 first surface
14 second surface
16 flank surface
16a first end
16b second end
17 cutting edge
18 primary cutting edge
19 secondary wiper edge
20 curved corner
22 countersunk bore
24 central, longitudinal axis
26 planar central region
28 boundary
30 rake face

100 cutting tool
112 tool body
113 central, longitudinal axis
114 cutting end
116 pocket
118 mounting end
119 mounting screw

200 workpiece

R radius
P point
LC length (primary cutting edge)
LW length (secondary wiper edge)
LT total length