Working Load Limit is an important term often used on job sites and when discussing slings and other rigging equipment. It is important to have a comprehensive understanding of Working Load Limits, as well as understand how it’s different from other ratings. This will help you to safely use all of your rigging products.
Defining Working Load Limit
Working Load Limit is defined as the maximum load to be applied to a product when the load is uniformly applied in a straight line pull only. Avoid side loading or angular loading unless otherwise noted by the manufacturer. According to OSHA, “Employers must ensure that rigging equipment not be loaded in excess of its recommended safe working load as prescribed on the identification markings by the manufacturer.” (OHSA 1926.251(a)(2)(ii)). For that reason, all rigging equipment must have identification that clearly states the working load limit. Qualified Riggers should then always be sure to check the working load before using their rigging products. This will help ensure their safety and the safety of others around them.
Breaking Strength
There are several other ratings that differ from Working Load Limit, such as Breaking Strength. Breaking Strength refers to the point at which the rigging will fail. Always use Working Load Limit when choosing rigging, not breaking strength. Breaking strength is helpful, however, when looking at a piece of rigging’s design factor. Design Factor is simply the ratio between Working Load Limit and Breaking Strength. For example, the Eye Grab Hooks – OG have a Design, or Safety, Factor of 4:1 which means the Working Load Limit is ¼ of the Breaking Strength.
Tips for Safe Rigging
When using your rigging, you need to know the weight of the load in addition to the Working Load Limits of the equipment used for the lifting. There are a lot of items to consider for safe rigging, and they can all be covered in one of our training courses. Additionally, our article “How to Recognize When A Sling Should Be Removed from Service” is a great outline on inspecting your slings.