Understanding Breaking Strength and Elongation in Polyester PET Strap

Breaking strength and elongation are the two most important mechanical properties of PET strap (polyester strap). Breaking strength determines how much load a strap can secure, while elongation determines how the strap behaves under load—whether it maintains tension or stretches excessively. According to ASTM D3950 specifications, both properties must be tested and verified to ensure performance . This guide explains what these properties mean, how they interact, and how to use them for selecting the right PET strap for your application.