Tear strength is a property commonly used to compare cut growth propagation in a rubber-like material. In actual application, especially where impingement of a foreign material is constantly damaging the surface of the part, it is important that the extension of the rupture be kept to a minimum. Polyurethanes, due to the nature of their chemical composition, possess an advantage over conventional rubbers. This holds true over a broad temperature range.

Test Procedure to Measure Tear Strength ASTM Method D624, D1938 and D470
The tensile force necessary to cause tearing over a given length, expressed in pounds per various linear inches (pli). Specimen shapes are used for the test.