It is the SAFE WORKING LOAD that should be applied to a given piece of equipment, be it chain, web or wire rope. It is a portion of the nominal strength of the chain, web or wire rope, usually expressed as a ratio or percentage. Some manufacturers use the term “RATED CAPACITY.”
Sometimes you will see products marked “capacity” or “maximum capacity”. This is not necessarily the Work Load Limit and you should get clarification before using the product. B/A Products Co. always uses WLL, which is the most essential, precise piece of information.
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The “Working Load Limit” (rated capacity) is the maximum load that shall be applied in direct tension to an undamaged straight length of chain. Per NACM Standards.
The “Proof Test” (manufacturing test force) is a term designating the minimum tensile force which has been applied to a chain under a constantly increasing force in direct tension during the manufacturing process. These loads are manufacturing integrity tests and shall not be used as criteria for service or design purposes. Per NACM Standards.
The “Minimum Breaking Force” is the minimum force at which the chain during manufacture has been found by testing to break when a constantly increasing force is applied in direct tension. Breaking force values are not guarantees that all chain segments will endure these loads. This test is a manufacturer’s attribute acceptance test and shall not be used as criterion for service or design purposes. Per NACM Standards.
B/A Products uses a 3.55 to 1 ratio for winch lines, per SAE Specification: B30.5. These ratings are set by ANSI/ASME, OSHA, The Wire Rope Technical Board and AWRF. * OSHA calls out that wire rope used for overhead lifting be rated at 5:1.
Web straps will either be a 3:1 when used as a tie down, or a 5:1 when used as a sling. Check the tag to determine your straps’ rating. These ratings are set by The Web Sling Tie Down Association.
The permanent distortion of materials under applied stress after overload or other misuse.
eb straps will either be a 3:1 when used as a tie down, or a 5:1 when used as a sling. Check the tag to determine your straps’ rating. These ratings are set by The Web Sling Tie Down Association.
That process of lifting that would elevate a freely suspended load to such a position that dropping the load would present a possibility of bodily injury or property damage. Per NACM Standards.