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What is thinning?
Thinning is a process in which the chisel edge (the non-cutting edge) of the tip of the drill is thinned so that the blade is applied to the center of the drill.
It lowers the thrust resistance and makes it easier for the drill to cut into the workpiece.
It also has the effect of dividing chips into smaller pieces, making them easier to discharge.
Reference: What is thinning?
By thinning the chisel edge (the part that is not a cutting edge) at the tip of the drill, the blade is applied to the center of the drill.
Reduces thrust resistance and makes it easier to screw the drill onto the workpiece.
| (1) With thinning | (2) No thinning |
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(A) Cutting edge (B) Chisel edge thinning (C) Thinning |
(A') Cutting edge (B') Chisel edge remains wide |
References: point angle and Thrust Resistance
| point angle 118° | Bigger point angle |
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point angle is easier to enter the smaller one (sharp angle) R: Cutting force R1: Thrust resistance: The force of resistance applied in the opposite direction to the direction of travel R2: Rotational force |
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