If you have a plumbing project that requires cutting through cast iron, the best way to make sure you get a clean, even cut is to use a pipe-cutting tool. Such tools are often available at most hardware stores.
Cast iron pipe provides an incredibly durable and reliable material for plumbing. It can be used in drains, sewers and water mains and will generally last for years without requiring any maintenance. If you need to cut cast iron pipe, you'll need to use some specialty tools.