We are Qingdao Fortune Anchor Chain Co Ltd, our factory can produce the marine cast iron sinkers, the cast iron sinker's basic weight is from 1ton to 10ton of each pce.The marine cast iron sinker is often used in the sea anchored with the mooring chains for the navigation buoy or other usages. We can also produce the cast iron sinker as customer required shape, weight and sizes. Pls contact with us   mooringchain@yahoo.com