Page "learned" Paragraph 1280

It is difficult to measure the direction and magnitude of R directly.

In actual practice, the values most readily amenable to measurement are the cutting force Af and the shear angle Aj.

These two values and the rake angle **yc are sufficient to determine the other parameters of these relationships.

**yc is defined by the geometry of the knife ; ;

**yf can readily be determined by measuring the thickness of the coating before and after cutting from the substrate ; ;

Af is instrumentally determined.

From Fig. 6 the relationship between these parameters can readily be derived and the cutting force is Af where **yl is the shear strength of the coating and is a parameter of the coatings material, W is the width of the removed coating and T is its thickness.