Fabric tear and tensile strength mean very different things. Understanding the differences can help you make correct decisions when one is failing.  

People often think that tear and tensile strength of a fabric are the same thing. While they are related, they measure totally different things.

Tear strength refers to a fabric’s ability to resist tearing when a force is applied to it. It is typically measured by applying a force to a small cut made in the fabric and measuring the force required to continue the tear. The essential part is that tear strength measures an already cut/ruptured fabric. Hence, it is the force required to continue the rupture to the full piece of fabric/garment.

Tensile strength, on the other hand, measures a fabric’s ability to resist stretching or breaking when a force is applied to it. It is typically measured by pulling on the fabric until it reaches its breaking point. Tensile measures an intact fabric, thereon force is applied to rupture the strength. 

While tear and tensile strength are both important measures of a fabric’s durability, they are not interchangeable. A fabric with high tear strength may not necessarily have high tensile strength, and vice versa. It’s important to consider both properties when choosing a fabric for a particular application.

For example, a very dense fabric will always have very good tensile properties, but often have very poor tear stength.