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US 12,734,591 B2Granted
Drill and method of producing drilled product
AssigneeSubaru Corporation
InventorsRei Nakamoto, Tsukasa Yokono, Aoi Mase, Shunsuke Saito
Life of this patent
Estimating the term…
Abstract
A drill has two to four cutting edges each made of cemented carbide or polycrystalline diamond. Helical flutes are formed alternately with the cutting edges. X-shaped thinning has been applied to the cutting edges. A rake angle of the cutting edges is not less than 30 degrees and not more than 40 degrees. A clearance angle of the cutting edges is more than 0 degrees and not more than 8 degrees. The cutting edges each has a honed face by chamfer honing. A honing angle of the honed face is not less than −3 degrees and not more than 8 degrees.
Claims20
A drill, comprising:
- a body having two to four cutting edges each comprising at least one of cemented carbide and polycrystalline diamond such that the cutting edges are forming helical flutes alternately,
- wherein X-shaped thinning has been applied to the cutting edges, the cutting edges has a rake angle in a range of 30 degrees to 40 degrees and a clearance angle of more than 0 degrees and not more than 8 degrees, and each of the cutting edges has a honed face by chamfer honing such that a honing angle of the honed face is in a range of −3 degrees to 8 degrees, the drill is a double margin drill having fluted lands on each of which two margins are formed such that each of the fluted lands is formed between adjacent two of the helical flutes, and a cutting edge length of the drill, defined as a flute length of the helical flutes, is longer than five times a tool diameter of the drill.
Dependencies are inferred from the claim text.