Working Load Limit

The Working Load Limit (WLL) or Safe Working Load (SWL) is the maximum load which should ever be applied to the product under any condition. The Working Load Limit is based on a load being uniformly applied in a straight line pull.

Minimum Breaking Strength

Do NOT use Minimum Breaking Strength (MBS) for design or rating purposes. Use the Working Load Limit (WLL) instead. Minimum Breaking Strength is an average figure at which samples have been found to break under laboratory conditions in straight line pulls with constantly increasing loads. These conditions are rarely duplicated in actual use. The Minimum Breaking Strength applies to new and unused wire rod for Wire Rope, Aircraft Cable, and Chain.

Proof Load

The load a product can withstand during quality control test for the purpose of detecting defects and deformation in the material, usually twice the Working Load Limit.

Matching Components

All attachments used with chain and wire rope must be of suitable material, type and strength to provide adequate safety protection. Attachments should have Working Load Limits at least equal to the other components with which they are used.

Inspections Warning

No product can operate indefinitely at its rated capacity. Cable, wire rope, chain, and their attachments must be inspected regularly by a trained or qualified individual for visible damage, distortion, elongation, corrosion, cracks, nicks, or abrasion, which may cause failure or reduce the strength or ability of the product to perform safely.

Shock Loads

Loads which exceed the static caused by a rapid change of movement, such as jerking, impacting, or swinging of load. Working Load Limits will not apply.

Making Requirements

The US Customs law requires that the end user of imported products be informed of the country of origin. All imported products sold by Susquehanna Wire Rope are marked accordingly. Re-sellers are responsible to relay this country of origin information to the end user.


  • No product can operate indefinitely at its rated capacity.
  • Avoid shock loads and side loads.
  • Keep out from under a raised load.
  • Never exceed the Working Load Limit.
  • Inspect your rigging products regularly.