Unpopular opinion: I think using a 3/8 inch drive for those tight boiler tube nuts is better than a 1/2 inch.
I was working on a 1958 Cleaver-Brooks unit last month and kept rounding off the corners in a cramped space. My buddy in Toledo said to try a 3/8 drive with a thin-wall socket and a cheater bar for the final torque. It gave me just enough swing room without slipping. Anyone else have a go-to trick for those impossible back nuts?
Yeah, those things are the worst. I finally bought a set of those six-point sockets just for that job. Makes a huge difference, way less likely to strip. What are you working on that's giving you so much trouble?