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26.2 Blade Parameter Definitions and Geometry Calculations

Two of the most important input parameters of the blade geometry calculation
after the pressure angle are the effective side rake angle, which indicates the
“sharpness” of the blade and the effective cutting edge hook angle, which indi-
rectly defines the top rake angle. It might be important at this point to mention
that for the cutting performance and for good tool life, the effective cutting edge
hook angle is the most important parameter. Because the top rake angle and
effective cutting edge hook angle are connected, the 3-face blade calculation
program attempts to define a blade geometry which achieves the desired ef-
fective cutting edge hook angle. Only in cases where this is not possible due to
geometry limitations, will the closest possible value be used as the result.

Figure 3: Cutting plane and kinematic velocity vector

Figure 4: Coordinate systems of 2-face blade (left) and 3-face blade (right)

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