What about a 4" angle grinder? Will that fit up in there? Just trying to help you out cause I know what it is like to cut and cut and feel like you are making no progress at all. When I roust-a-bouted in the oilfield and had to cut pipe on the location we did it with a oversized hack saw. And 4" schedule 80 pipe is not easy to get through, and then we had to thread it... :evil: