unusual tools

Not fiber related. I am interested in how things work and how things are made. They're doing a bunch of construction outside my office-- ripped out walls, are re-plumbing and re-wiring everything across the hall. A few weeks ago I saw them trundling in a cart with a big heavy machine of some sort.
"What's that?" I asked.
"Pipe threader."
??
"It threads pipe. You know, so they screw together."
Oh! of course. Today dodging a ladder I ran across one of the pipe guys.
"You want to see how that thing works? Come on back here, I'll show you."
It's sort of like a lathe, I guess, the pipe is turned between four vicious looking toothed things that scrape out the threading. It gets so hot they have to pour oil on it as it works. Pipe threader. Wow.