Add some carbide cutting disks to a chain wrench and you have a tool designed for cutting cast iron drain pipes, but also used in rock shops to break open geodes (round, hollow rocks with interesting crystal formations inside). Rocks, like cast-iron pipes, are very hard, and they don’t bend: they only break if stressed too much. You don’t turn it around, cutting deeper and deeper. Instead it stays stationary, and you just make it tighter and tighter until the pipe, or the rock, cracks.
Location: Not Mine
Have you used this tool? Think my description is all wrong? Have a better example? Comment now with any thoughts you have about this tool!