Fibre Core vs Independent Wire Rope Core (IWRC): Complete Guide

Fibre core or IWRC? This complete guide from CML SARL compares strength, crush resistance, flexibility, heat tolerance and corrosion behaviour of wire rope cores to help you choose the right rope.

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Every stranded wire rope has a core at its centre. The core supports the outer strands, keeps them in position and influences the strength, flexibility and crush resistance of the whole rope. The two main options are a fibre core (FC) and an independent wire rope core (IWRC). A third option, the wire strand core (WSC), is used mainly in smaller ropes. CML SARL regularly advises customers in Douala, Kribi and the mining regions of Cameroon on this choice. Here is everything you need to know. ### What Is a Fibre Core (FC)? A fibre core is made of natural fibres (traditionally sisal or other plant fibres) or synthetic fibres, most commonly polypropylene. The core is lubricated during manufacture and acts as a reservoir of lubricant for the strands. Main characteristics: - Very flexible, easy to handle and coil. - Lighter than an equivalent rope with steel core. - Lower breaking force than IWRC for the same diameter and grade. - Poor resistance to crushing on drums, especially multi-layer drums. - Limited heat resistance: fibre cores should not be used at elevated temperatures (typically above about 80 to 100 degrees Celsius, depending on the fibre). - Natural fibre cores can rot when water penetrates, a real risk in tropical humidity. ### What Is an IWRC? An independent wire rope core is a small complete wire rope, usually a 7x7 construction, placed at the centre of the main rope. The outer strands are laid around this steel rope. Main characteristics: - Higher breaking...