Ball end mill
AssigneeSumitomo Electric Industries, Ltd.
InventorsNagatoshi Kunimori, Yasuyuki Kanada
Life of this patent
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Abstract
The purpose is to improve the surface roughness Rz of a cut surface to 1.6 μm or under in cutting e.g. hardened steel. The ball end mill has a cutting blade made of a polycrystalline hard sintered material containing 20 to 95 vol % of cubic boron nitride. The cutting blade has a ridge portion having a radius of curvature of 5 to 30 μm. A flank and a rake face or a negative land of the cutting blade connect smoothly with the ridge with the radius of curvature. The ridge portion of the cutting blade has a surface roughness of 0.1 to 1.0 μm in terms of 10-point average roughness (Rz).
Claims20
A ball end mill comprising a cutting blade formed of a polycrystalline hard sintered material containing 20 to 95 vol % of cubic boron nitride,
- said cutting blade having a ridge formed into a curve having a radius of curvature of 5 to 30 μm,
- a flank and one of a rake face and a negative land of said cutting blade connecting smoothly with said ridge having said radius of curvature,
- said ridge having a ten point average surface roughness (Rz) of 0.1 to 1.0 μm.
Dependencies are inferred from the claim text.