[TheForge] Re: A-36 vs 1018

[Thomas A. Troszak]

> So one question is does 1018 and/or 1020 come in hot-rolled?
> And can someone tell me the exact difference between A36 and 1020?
> I think I know, but I figure I might as well just ask anyhow.

Yes, both are available both forms.

If you look at the ASTM specs for steels you notice that they overlap, that
is, the actual chemistry of some batches could put that batch into more than
one designation.  If I recall correctly, the specs for A-36 allow a wider
tolerance for Mn and S, but I don't have the book in front of me.

Anyway, in my experience, every batch of steel is different, and every bar
is different.  In my opinion, the few points of carbon diff. between 1020
and A-36 would probably not be noticable for forging purposes.   I have
forge welded both materials successfully.

The real difficulty comes from steel that is say, A-36 "chemistry only".
That means that the particular sample from the particular heat passed the
chemistry for A-36, but the entire heat and all the bars made from it are
still complete crap because the heat was poorly mixed, there are slag and
other inclusions, and the materials are not evenly mixed. Just having the
right amount of carbon does not in any way guarantee a good product.

I have purchased plenty of steel over the years that delaminated, spalled
off surface chunks, ate my saw blades, or just plain fractured for no good
reason, and I think it is the quality of the heat that matters..

Tom Troszak