ASTM D638 – Tensile Properties of Plastics

Standard: ASTM D638 Standard Test Method for Tensile Properties of Plastics

Scope: Per ASTM D638: "This test method covers the determination of the tensile properties of unreinforced and reinforced plastics in the form of standard dumbbell-shaped test specimens when tested under defined conditions of pretreatment, temperature, humidity, and testing machine speed."

Products: Plastics (1.0 mm or thicker)

Procedure: Dumbbell- or dogbone-shaped specimens are prepared, and two gauge marks are precisely placed on the specimens to establish the gauge length. The initial length between these marks is then measured before placing the specimens into the grips of the test machine. An extensometer is then fitted over the gauge length to record the extension in the specimen during testing. The test machine pulls the specimens in tension at a specified grip separation rate until failure. Throughout the test, load and deflection (or stress and strain) measurements are taken in order to characterize the materials under test.

Result: Test results such as tensile stress, yield stress/strain, tensile strength, and elongation may be reported.