Twist drill for metal machining
AssigneeSeco Tools AB
InventorsAnders Bjork, Par Nordberg, Christian Carlsson
Life of this patent
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Abstract
A long twist drill includes a shank and a drill body having a drill tip (16). The twist drill has a length L and an outer diameter D, and has a cemented carbide or high speed steel substrate and a coating of at least one layer. The quota L/D is at least 16. The twist drill has two cutting segments at the tip and two flutes chip. The twist drill is provided with holes for fluid opening in the tip. The twist drill has an axial web thinning angle GAA, which is 40 to 50°. The twist drill further has a web that back tapers such that a web diameter gets smaller in a direction away from the tip towards the shank within an axial distance.
Claims19
A twist drill comprising:
- a shank;
- a drill body having a drill tip, and having a length and an outer diameter, and including a cemented carbide or high speed steel substrate and a coating having at least one layer, wherein a quota L/D is at least 16;
- two cutting segments at the tip and two chip flutes;
- a plurality of holes for fluid opening in the tip;
- an axial web thinning angle, wherein the axial web thinning angle is 40 to 50°;
- and
- a web which back tapers from such that a web diameter gets smaller in a direction away from the tip towards the shank within an axial distance, wherein the back taper ends at the axial distance and transfers into a cylindrical web with a constant diameter.
Dependencies are inferred from the claim text.