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.
For many materials, there may be a specification that requires the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Table 1 of Classification System D 4000 lists the ASTM materials standards that currently exist.