REDWIRE Bergen Cable’s tips on how to calculate wire-rope stretch properly

April 10, 2023 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.

Posted by Bergen Cable Technology, Inc


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Wire rope is available from Bergen Cable.

Great products and unmatched expertise: these are the two factors that explain more than eight decades of international success for Bergen Cable. The supplier offers ample cable resources on its website, including a Cable 101 page, which contains a section about wire-rope stretch – a trait that businesses should consider during product selection. Customers should also take the stretching factor into account when inspecting the wire rope that employees use. Bergen suggests checking the stretch regularly when the wire rope is carrying a load, as per most occupational health and safety guidelines.

Elastic and structural stretch

While some people use the term “wire rope” as if it were a synonym for “cable”, the former actually refers to rope with diameters larger than 3/8 of an inch. The two primary factors that affect stretch are elastic and structural stretch. Wire elongation causes elastic stretch, while stretch results from a combination of lengthening the rope lay, compressing the core, and adjusting the wires and strands to the load that the rope is holding.

According to Bergen, among the variables that affect structural stretch are the ore size, the length of the lays, the rope construction, and the loads and amount of bending that is imposed on the wire rope. One can estimate the quantitative value of the structural stretch by multiplying the length of the rope by 0.005 when it is carrying a medium-weight load, by 0.01 for a heavy load, or by 0.0025 for a light load.

Elastic wire-rope stretch is proportional to load weight and rope length when it holds a load under the elastic limit of the rope. The elastic limit of galvanized wire rope is usually around half of its breaking strength, or about 60 per cent when dealing with stainless steel rope. Elastic stretch is inversely proportional to the wire rope’s metallic area and modulus of elasticity. To calculate the elastic stretch in feet, just multiply the load weight in pounds by the rope length in feet and then divide the answer by the metallic area in square inches multiplied by the modulus.

To learn more, contact Bergen.


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Posted by Bergen Cable Technology, Inc


Mfr Mechanical Cable, Cable Assemblies & Push-Pull Controls. Original Mfr Of Safety Cable, A Patented Fastener Reten... Read more

Contact supplier