Elongation at break
What is the elongation at break?
Elongation at break, also known as tear elongation, is a parameter determined in a tensile test. A standardized test specimen is pulled uniformly until it breaks. The change in length at the moment of break, relative to the initial length, yields the elongation at break as a percentage. A value of 200 percent means that the specimen could be stretched to three times its original length before breaking. Elongation at break thus describes the elasticity of the elastomer, not its strength.
Why Elongation at Break Is Important for O-Rings
In practice, elongation at break is particularly relevant during installation. An O-ring often needs to be pulled over an edge, a flange, or a shaft without tearing. A material with sufficient elongation at break can withstand this brief overstretching. At the same time, this value serves as an indicator of the material’s overall condition: if an elastomer becomes brittle due to aging or temperature, its elongation at break decreases. It is therefore considered in conjunction with tensile strength to assess the material’s mechanical load-bearing capacity.
- Elongation at break is the elongation up to fracture in a tensile test, expressed as a percentage.
- It describes the material's ductility, not its strength.
- Adequate elongation at break is particularly important for installation over edges.
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[TODO Luke: Specific values for elongation at break (%) for each mixture are not available in werkstoffdaten.md. If a range of values is desired, please add the values from the data sheets.]