Cast iron pipes are commonly used in plumbing for main sewage lines and drainage systems due to their high durability, longevity, and resistance to corrosion. They're particularly favoured for underground installations, where their strength can withstand the soil's pressure and environmental conditions. Additionally, cast iron's sound-dampening qualities make it a preferred choice for reducing noise in waste disposal systems within buildings. Best tool for cleaning & descaling Cast Iron pipes: When cleaning or descaling Cast Iron pipes it is good to know that The Cast Iron Pipes can almost always withstand even the most aggressive hits from the Chain Knocker. This is why we recommend going with the Medium Duty Chain Knockers for aggressive descaling tasks. If you personally prefer Heavy Duty Chain Knockers, those will also work perfectly. Using Light Duty Chain Knockers in Cast Iron will most likely be more time consuming, but it will eventually get the job done.