I’m a long-time tool-renter. It’s a great way to go for all kinds of needs. Years ago I had to cut a 4″ iron (not steel) pipe deep in a hole in my backyard. (The pipe led to a septic system that was supposed to be 18″ underground, but was actually 6 feet underground.) I needed a clean cut, and iron has a way of shattering if you hit it wrong. I tried a variety of methods, including an abrasive cutting wheel hooked up to a circular-saw-like motor. Nothing worked. Then the resident old-timer at my local tool rental place recommended a chain cutter, similar to this one, though much more well-used.
It consists of a flexible chain that you wrap around the pipe and lock in place. Inside each link of the chain is a small circular cutting blade. Once locked in place, you use the handles to ratchet the chain tighter and tighter around the pipe. The circular blades provide even pressure from all sides, and within a few ratchets you hear a satisfying snick sound and your pipe is cut clean and even. This was definitely a cool tool, one that made an otherwise impossible situation ridiculously easy.