Choosing the right chain for the job can be a bit confusing, so here are a few tips to help you choose wisely: REGULAR chains or CYCLONE chains? The REGULAR chains come with 1, 2 or 3 independent chains. These can be adjusted (to adapt to the pipe diameter) and are most suitable for removing blockages. The CYCLONE chain has a fixed diameter and more chain links on the outside diameter. The perfect tool for descaling pipes. Chains WITH hard metal bits and chains WITHOUT hard metal bits? Chains WITHOUT hard metal bits are suitable for PVC pipes while the chains WITH hard metal bits are meant for cast iron, vitrified clay, copper, ceramic or galvanised steel pipes.