Scope:

Shear Strength Test by ASTM D732 is used to calculate the load at which a plastic or film punctures when sheared between two metal edges. Shear strength values are significant in designing film and sheet products that are exposed to shear loads, as well as in applications where applied crushing loads are a concern.

Test Procedure:

For the ASTM D732 test procedure is carried out by clamping a test sample connected to a 1-inch punch between two metal fixtures. Then, a male punch is pushed into the hole in the metal fixture, creating shear around the hole’s side. Finally, a universal testing machine is used to push the punch until shearing of the sample occurs.

Specimen size:

The samples for the ASTM D732 test are 2-inch-diameter disks or 2-inch-squared plates with thicknesses varying from 0.05 to 0.5 inches. To place the sample in the fixture, a 7/16th inch hole is drilled through the middle of it.

Data:

The outcomes are represented as shear strength and are given in MPa or psi units. The shear strength is determined by measuring the shear force divided by the area of the sheared edge. Circumference of the punch impact multiplied by the thickness of the sample gives the area of the sheared edge. 

Conclusion:

ASTM D732 is a standard test method which helps compare shear performance between materials and also to obtain engineering design data.