FX CHAINS U.S. Tsubaki FX chains feature excellent durability and flexibility for tough applications such as in concrete mixers, earth moving equipment, and mining machines. 1. FX chains are interchangeable with ASME/ANSI standard chains and can operate on the same ASME/ANSI standard sprocket. 2. Increased clearance between pins and bushings allows the chains to accommodate a 4 inch lateral side bow and an 8 degree twist per 4 feet of chain.