A micro end mill includes a shank made of a first material and a cutting tip made of a second, different material that is bonded to the shank. The first material can be, for example, carbide or high speed steel (HSS), and the second material can be, for example, cubic boron nitride (CBN), polycrystalline cubic boron nitride (PCBN), ceramic or polycrystalline diamond (PCD). The micro end mill is manufactured by producing a billet made of Superhard material using laser radiation, bonding the billet to a shank of the end mill, and removing material from the billet using laser radiation to produce a cutting tip made of the Superhard material. The laser radiation may comprise a laser beam encased in a water jet or a laser beam with a non-Gaussian intensity profile.

A rotary cutting tool or end mill is provided, the tool comprising a plurality of pairs of diametrically-opposed, symmetrical, helical flutes formed in a cutting portion of the tool body, wherein the pitch between at least one pair of adjacent helical flutes is less than or greater than the pitch of at least one other pair of adjacent helical flutes in at least one radial plane along the axial length of the flutes, a plurality of peripheral cutting edges, wherein at least one of the peripheral cutting edges has a radial rake angle different from radial rake angle of a peripheral cutting edge of a different helical flute.

A rotary cutting tool or end mill is provided, the tool comprising a plurality of pairs of diametrically-opposed, symmetrical, helical flutes formed in a cutting portion of the tool body, wherein the pitch between at least one pair of adjacent helical flutes is less than or greater than the pitch of at least one other pair of adjacent helical flutes in at least one radial plane along the axial length of the flutes, a plurality of peripheral cutting edges, wherein at least one of the peripheral cutting edges has a radial rake angle different from radial rake angle of a peripheral cutting edge of a different helical flute.

A contoured rake face cutting tool and method of making is disclosed. A rotary cutting tool with a plurality of teeth can cause damage to a work piece during cutting. By orienting the cutting angle of the teeth relative to the rotational central axis to high shear angle such as 50 or 70 degrees, the tool creates a high compression cut which is cleaner and less damaging to the work piece. The cutting surface itself is profiled, i.e. non-planar, such as concave or convex or other non planar shape, which is preferably formed into an ultra-hard material which is supplied for use in a planar form.

A contoured rake face cutting tool and method of making is disclosed. A rotary cutting tool with a plurality of teeth can cause damage to a work piece during cutting. By orienting the cutting angle of the teeth relative to the rotational central axis to high shear angle such as 50 or 70 degrees, the tool creates a high compression cut which is cleaner and less damaging to the work piece. The cutting surface itself is profiled, i.e. non-planar, such as concave or convex or other non planar shape, which is preferably formed into an ultra-hard material which is supplied for use in a planar form.

A rotary cutting tool includes a shank portion and a cutting portion extending from the shank portion to a cutting tip. The cutting portion has a plurality of blades separated by flutes. Each of the blades includes a relief surface and a radial cutting edge formed at an intersection between a respective flute and the relief surface. The relief surface includes an inner eccentric relief immediately adjacent the radial cutting edge and an outer eccentric relief immediately adjacent the inner eccentric relief. The inner eccentric relief is formed with an inner eccentric relief angle, , of less than about 5 degrees, and wherein the outer eccentric relief is formed with an outer eccentric relief angle, , of between about 5 degrees and about 15 degrees. A method of making the rotary cutting tool is also described.

A rotary cutting tool includes a shank portion and a cutting portion extending from the shank portion to a cutting tip. The cutting portion has a plurality of blades separated by flutes. Each of the blades includes a relief surface and a radial cutting edge formed at an intersection between a respective flute and the relief surface. The relief surface includes an inner eccentric relief immediately adjacent the radial cutting edge and an outer eccentric relief immediately adjacent the inner eccentric relief. The inner eccentric relief is formed with an inner eccentric relief angle, , of less than about 5 degrees, and wherein the outer eccentric relief is formed with an outer eccentric relief angle, , of between about 5 degrees and about 15 degrees. A method of making the rotary cutting tool is also described.

A base material for a hard sintered body includes a pillar portion having a central axis and extending in the axial direction of the central axis. The pillar portion has a first outer peripheral portion, a second outer peripheral portion, and a protruding stripe portion. In the cross-sectional view, one side portion of the first outer peripheral portion extending in a circumferential direction or a radial direction is located inside the other side portion. In the cross-sectional view, one side portion of the second outer peripheral portion extending in the circumferential direction or the radial direction is located outside the other side portion in the radial direction. The protruding stripe portion is located in a connection portion between the other side portion of the first outer peripheral portion and one side portion of the second outer peripheral portion, and protrudes outward.

A base material for a hard sintered body includes a pillar portion having a central axis and extending in the axial direction of the central axis. The pillar portion has a first outer peripheral portion, a second outer peripheral portion, and a protruding stripe portion. In the cross-sectional view, one side portion of the first outer peripheral portion extending in a circumferential direction or a radial direction is located inside the other side portion. In the cross-sectional view, one side portion of the second outer peripheral portion extending in the circumferential direction or the radial direction is located outside the other side portion in the radial direction. The protruding stripe portion is located in a connection portion between the other side portion of the first outer peripheral portion and one side portion of the second outer peripheral portion, and protrudes outward.

A body of a cutting tool may include a shank and a tip having spaced-apart, helical flutes. Each spaced-apart, helical flute may include a helical cutting edge extending from a tip bottom, adjacent a shank top, to a tip top. The tip may include chip gash paths. Each chip gash path may be recessed between two of the spaced-apart, helical flutes, and extend from the tip bottom to a tip top portion. The body may include helical coolant channels extending from entrances at a shank bottom, to within a shank interior, to within a tip interior, to tip coolant orifice exits. The coolant orifice exits may be disposed in the spaced-apart, helical flutes adjacent the chip gash paths or disposed in relief surfaces extending from the tip top downward to the chip gash paths. The coolant orifice exits may be spaced-apart from the tip top.