Understanding Break Strength vs. Working Load Limit
What is Break Strength vs. Working Load Limit?
When it comes to ratchet straps, winch straps, and just about any other type of strap in the cargo industry, the words Working Load Limit (WLL) and Breaking or Break Strength are commonly seen.
Every piece of webbing, buckle, ratchet, and end hardware has its own number associated with both its WLL and Break Strength. These numbers let the user know how much weight that object is capable of securing. Although usually clearly stated, many people do not fully understand what these terms mean.
When it comes to fragile materials or heavy loads, it is extremely important to make sure that the strap securing it is able to do so without breaking.
Whenever you see the words “Break Strength” they are referring to the point at which any point of your cargo strap will fail. Break strength is determined by the WEAKEST POINT of the strap (webbing, end fittings, or tensioning device.)
For example, when a ratchet strap is made with end fittings, webbing, and a ratchet all with 10,000 pound break strength, then the overall break strength of the finished product will stay 10,000 pounds. However, if the same strap was made with a ratchet that had an 8,000 pound break strength, then that would reduce the overall product strength to 8,000 pounds; even though the webbing is rated for 10,000 pounds.
Working Load Limit
Working Load Limit or WLL refers to the maximum allowed weight. A winch strap with a WLL of 5,000 pounds, should not be used to secure any load above that weight. Working Load Limit is always 1/3 of the breaking strength. Therefore a strap with a breaking strength of 15,000 pounds, will have a Working Load Limit of 5,000 pounds.
It is extremely important to understand the differences and make sure that whenever you are securing a load, you are doing so with a strap that is able to handle that item’s weight. A failure in the strap could not only be costly, but dangerous as well. In most cases these limits will either be printed, or tagged on each strap, be sure to reference them before use.
An example of the Working Load Limit printed on a Cargo Equipment strap.
An example of a tag sewn on a Cargo Equipment strap with the Working Load Limit.
Tie down straps come in a large range of sizes to ensure your load is secure and you don’t exceed working load limit.
View the full line of ratchet straps and fittings Cargo Equipment Corporation has to offer.