Understand the difference between a test result for webbing and a rated capacity for a finished assembly.
Breaking strength is a test result
Breaking strength describes the force at which a specimen fails under a specified test procedure. The method, sample preparation, gripping, conditioning and reported result all matter. ASTM lists D6775 as a method for measuring breaking strength and elongation of textile webbing within its stated scope. Ask the laboratory or supplier to identify the standard and edition used.
A working load limit is an application rating
A working load limit or rated capacity applies to a defined product and its stated conditions of use. It cannot be obtained safely by treating the breaking strength of a roll as the rating of a sewn strap. Hardware, seams, geometry, angles, wear and operating conditions may affect the complete system.
Lifting and life-safety uses require specific engineering
For lifting slings, use a properly identified, rated finished product and follow the sling manufacturer’s instructions and applicable requirements. OSHA explains that sling rated loads depend on factors including hitch type and loading angle. Consult a qualified person and the applicable standards. Do not use ordinary webbing based on a generic website description for lifting or fall protection.
Specify the evidence
Request the exact specimen or assembly, test method, conditioning, units, sample count, test results and product identification. Agree on acceptance criteria before production.
Frequently asked question
Can I divide breaking strength by a fixed number to get a safe load?
Do not infer a rating from a generic formula. The complete product requires a rating established for its design, application and governing requirements.
References
Explore woven webbing options or contact KVN to discuss a specification.