Shear strength obtained by a tool of the punch type is
one of the recognized methods of comparing materials or
obtaining data for engineering design. However, it must be
recognized that for end-use application there may be many
factors not taken into account in this test method, such as
stress-concentrating geometries and rates of shear, which can
profoundly affect shear strength. Moreover, the fact that the
shear strength is calculated by dividing the load by the area of
the sheared edge (circumference X thickness) should not be
interpreted as indicating that the shear strength value so
obtained is solely a material property, independent of thickness.