ASTM D638 Overview | Plastics and Elastomers | Tension Testing
ASTM D638 is one of the most common plastic strength specifications and covers the tensile properties of unreinforced and reinforced plastics. This test method uses standard “dogbone” shaped specimens under 14mm of thickness. A universal testing machine (tensile testing machine) is needed to perform this test. Prior to conducting ASTM D638, it is important to read the entire specification in the relevant ASTM publication.
First off, do not perform this test if you have films or elastomers. If you have film under 1mm in thickness use ASTM D882. If you have an elastomer use ASTM D412.