Tension Set

Significance and Test Method

Elastomers mainly deform elastically under load, in other words reversibly, but to a certain extent they also deform permanently. The degree of this permanent deformation allows conclusions to be drawn concerning the suitability of an elastomer for a specific application, as well as the degree of cross-linking of a finished part.

Significance for Application Technology

The tensile set, likewise the compression set, provides information about the resilience characteristics of elastomers under thermal load.

The Tension Set Test

The tension set is tested in accordance with ISO 2285 or DIN ISO 2285 at a defined temperature under constant elongation or constant load. We usually work with constant strain for the tension set test (TS test), as this application case is the more significant in reality.

Either an elastomer strip, a dumbbell test piece or, in sealing technology, an O-ring is used as a test specimen. The specimen is uniformly loaded with a certain elongation, usually 25 % or 50 %, at a defined temperature over a defined period. It is relaxed again directly after removal from the furnace (procedure A) or after a cooling process down to 23°C (procedure B).

The tension set describes the permanent elongation in relation to the absolute elongation and is expressed as a percentage of the absolute elongation.


Detailed information on the tensile deformation residual and its testing can also be found in our technical reports:

In the technical report you will learn how a TS test in accordance with DIN ISO 2285 is carried out, what significance the determined results have and how it is to be distinguished from a compression set test (CS test). In addition, the article describes the difference between the TS test in accordance with ISO and the tests specified in ASTM D412 and ASTM D1414.