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What is the effect of the torsion angle of a drill?
As for the effect of the helix angle, the standard twist is 30°.
For weak twisting, the sharpness is reduced, but the cutting edge strength is high.
The stronger the torsion angle, the sharper the edge, but the lower the cutting edge strength.
The stiffness of the drill is higher with weak torsion.
For weak twisting, the sharpness is reduced, but the cutting edge strength is high.
The stronger the torsion angle, the sharper the edge, but the lower the cutting edge strength.
The stiffness of the drill is higher with weak torsion.
Example: 12° |
Example: 30° |
Example: 40° |
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The helix angle of the drill and the shape of the cutting edge
Anything below 30° |
Above 30° |
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(A): Helix angle (= equal to rake angle (D))
(B): Chips(C): Rake surface
(D): Rake angle
(E): Clearance angle
(F): Flee