New fatigue testing required of chain manufacturers

Forklift truck manufacturers must now assure customers that the leaf chains used in their products meet rigorous new fatigue resistance standards.

The new regulations mark an update to ISO 4347 – the international standard governing the manufacture of the type of leaf chain used by forklift truck manufacturers to operate a lift truck’s mast.

The new standards, which will be formalised within the next 12 months, will make a particular impact on chain suppliers to forklift OEMs and dealers will be expected to conduct rigorous testing and supply additional customer information in order to comply with the ISO 4374 standard.

At present chain manufacturers are only required to demonstrate that their products comply with breaking load guidelines. The new fatigue element to testing and reliability claims will turn the spotlight on dynamic strength – proving endurance as well as high breaking load capacity.

This combination of standards should help users specify fit for purpose materials handling solutions. The new standards should encourage greater long term reliability in forklift products and reduce overall operational costs.

The proposed changes to ISO 4347 will require chain manufacturers to show that their chain will withstand a minimum dynamic load for at least 3 million cycles.

Jim Cameron, technical director of FB Chain and a member of the International Standards committee tasked with overhauling the current guidelines said: “A chain’s ability to provide good fatigue resistance whilst maintaining high breaking loads is a far more accurate guide to the chain’s quality and suitability.”

Mr Cameron assured that the new guidelines should not come as a burden to most good chain manufacturers who would already know the fatigue limits of their products.

Cameron encouraged all engineers looking to design in or replace a lift truck chain. To ensure they take fatigue levels as well as breaking loads into account. “Anyone tasked with acquiring new leaf chain should ensure that what they are buying has been thoroughly tested for both breaking load and fatigue resistance,” he stated.