What is stretching?

The stretchability of a material can be determined by comparing the length of the stretched material with the original length. The difference in length is usually given as a percentage, but the force required to produce the elongation can also be given in N/mm². IMPORTANT: In vibration technology, installed rubber parts (buffers, machine feet, etc.) should NEVER be under permanent tensile load. Natural rubber has the best elasticity with 7 to 30 N/mm². However, SBR and NBR can also have elongation values of up to 25 N/mm². Another important parameter is the elongation at break. This is the elongation (again expressed as a percentage) at which the sample tears. Natural rubber, chloroprene rubber, EPDM, SBR and butyl rubber have a high elongation at break. The test is defined in the DIN 53504 standard.