Rotary cutter for machining materials

Abstract

A rotary cutting tool. The tool has a body with outside diameter (OD), and outer surface, and a longitudinal axis, a plurality of flutes, helical in some embodiments. Flutes include a narrow leading edge land portion with circular segment profile and having flute cutting edge portions along a substantially uniform circumferential location, with an eccentric relief margin rotationally rearward of the narrow leading edge land portions. Face portions are provided with face cutting edge portions, and with a first dish portion adjacent each of the cutting edge portions sloping inwardly and downwardly generally toward a central longitudinal axis at a first dish angle alpha (α) Corner blend portions extend from flute cutting edge portions to the face cutting edge portions. Corner blend portions are provided in a variety of profiles, including an embodiment wherein the profile of the corner blend portions are truncated before the segment of curvature becomes tangential to the face cutting edge portions. Large core diameters of cutting tools are provided, which gives high strength when working with axial depths of cut of about three times outside tool diameter or less.

1 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having two flutes, said core diameter being at least sixty percent (60%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         2 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having three flutes, said core diameter being at least sixty percent (60%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         3 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having four flutes, said core diameter being at least fifty eight percent (58%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         4 . An endmill, as set forth in  claim 3 , wherein said core diameter is at least sixty percent (60%) of said outside tool diameter. 
     
     
         5 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having five flutes, said core diameter being at least sixty one percent (61%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         6 . An endmill, as set forth in  claim 5 , wherein said core diameter is at least sixty four percent (64%) of said outside tool diameter. 
     
     
         7 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having six flutes, said core diameter being at least sixty three percent (63%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         8 . An endmill, as set forth in  claim 7 , wherein said core diameter is at least sixty five percent (65%) of said outside tool diameter. 
     
     
         9 . An endmill, said endmill having an outside tool diameter and a core diameter, said endmill having seven flutes, said core diameter being at least sixty four percent (64%) of said outside tool diameter, and wherein said endmill comprises a usable cutting portion having a length of less than or equal to about three times said outside tool diameter, to thereby enable an axial depth of cut on a workpiece as deep as said length of said usable cutting portion. 
     
     
         10 . An endmill, as set forth in  claim 9 , wherein said core diameter is at least sixty eight (68%) of said outside tool diameter.