"Gas pipe" used relative to a steel bike isn't to be taken literally. It's a derogatory put-down insult of cheap steel bikes. "The thing is made of gas pipe". Sorta like, "did you get a good look at that Fred we just passed?" They didn't mean the dude's name was Fred lol!
Originally Posted by
rekmeyata
Gas pipe is not the same as steel used for bicycles. Modern gas pipe has steel, black iron, polyvinyl chloride (PVC), high-density polyethylene (HDPE) and copper; of course way back in the 1800's and early 100's gas pipe was used because that's all they had, but back then it didn't contain PVC or HDPE; and yet that stuff held up pretty decently, they did races across the world, touring trips across the world, TDF was done on that stuff, so it did hold up reasonably well.
Steel bike frames, depending how what it is can have different stuff in it. Reynolds 531 in it's earlier years was made of
either High Manganese, or High Molybdenum, I can't remember which; then they changed it to Manganese Molybdenum. That's different than Cromoly, Cro-mo. Since I don't know a lot about this stuff, so I'll refer you to a website: https://www.tekton.com/blog/crmo-or-crv-steel
You'll find the same sort of steel used in bike frames is also used in tools.