Steel type and source for a mini mill

I'll weigh in here a bit. If you can get the free machining plate, do it. If not, use the 1018 CRFB. Avoid A36 as much as you can. That is a structural steel spec, and it could be Anything that passes the 36000 tensile test. Thats all the spec means. I ran the machine shop in a testing lab for a short while. I got to hear way more than I wanted to about this issue. In some places in the far east, they take crushed cars and heat them up just enough to put them in the kneaders and rolls. Out comes rolled stock. Those disreputable outfits don't bother to sort the scrap at all, so there will be zones in the plate with copper, or aluminum, or high carbon contents, or weird alloying elements. I had a buyer for structural steel tell me stories of having to pick and choose plate a piece at a time with a PMI machine to get plate that would even meet the A36 spec.

Buy domestic if you can, and if not use an AISI spec rather than the ASTM structural spec. Your results will be more consistent at least.
 
Back
Top