keðju

Keðja, in Icelandic often appearing in the form keðju, is a flexible length composed of connected metal links designed to transmit force, secure loads, or guide movement. It is used in a wide range of applications, including lifting and rigging, towing, securing cargo, and as part of mechanical systems such as chain drives and conveyors. The term covers both heavy-duty industrial chains and lighter, everyday examples.

A keðja consists of individual links that are joined to form a continuous chain. The links can be made from various materials, most commonly steel or alloy steel for strength and durability, with stainless steel used where corrosion resistance is important. Lighter-duty chains may be made from other metals or engineered polymers. In addition to general purpose chains, specialized variants include roller chains used in machinery, welded chains, and chain slings designed for lifting loads. Some chains are designed for specific environments, such as high-temperature, chemical, or marine settings.

Technical characteristics used to specify a keðja include length, pitch (distance between adjacent pin centers), pin diameter, and the working load limit. Regular inspection is essential: look for wear, elongation, deformation, corrosion, and damaged links. Proper lubrication and alignment reduce wear, while overloading or impact can shorten chain life. When wear reaches a defined threshold, replacement is recommended to maintain safety and performance.

Etymology: the word is of Germanic origin and cognate with Danish kæde, Norwegian kjede, and Swedish kedja, reflecting a common North Germanic heritage for the term chain.