The tension test is very simple. A specimen of the material, usually a round rod or a flat bar, is pulled with a controlled tension force. As the force is increased, the elongation of the specimen is measured and recorded.

The relationship between applied load and resulting deformation can be observed from a plot of the data. This plot has little direct usefulness, however, because it applies only to the specific specimen (meaning the specific diameter or cross-sectional dimensions) used in the test procedure.