I’ve been having a bit of trouble sourcing steel tubes for my lowrider, but I found a place that can order me stainless steel (will take a few weeks, it seems) or for about half the price, they have “hot-rolled steel” ( .095 wall) that I could get right away. I’m not sure if that’s the same thing that’s listed as “DOM” in the build directions or if that’s something else entirely.
DOM (Drawn Over Mandrel) is a rolling process and the steel can be “hot” or “cold”
Hot rolled is faster and usually cheaper. The steel oxidizes slightly because of th extra heat, so you don’t get as smooth a finish, and the dimensional accuracy is not as good. It is likely good enough though, and while smoother is definitely better for what we want, it’s likely to be adequate. We aren’t doing things like running LMxxU linear bearings over it, the 22mm diameter skate bearings we’re using won’t get thrown off for this. (If it did, then the galvanized coating on 23.5mm conduit would pose a problem)
The overall strength of the end result will depend on the composition of the steel and a few other factors, hot or cold rolled is generally not one of them.
All in all though, hot rolled is an inferior product. If the cost is not a barrier, the stainless is nice. Cold rolled steel will be the most accurate dimensionally, and have good hardness to resist “flat spotting” under where the bearings roll. most stainless steel will deform under the bearings over time slightly.
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Thanks. As a woodworker and not a metal guy, navigating the jargon was getting a bit confusing. I think I’ll just go with the stainless for the smoothness and rust factors.