[TheForge] Re: cold drawn steel

[Thomas A. Troszak]

somebody wrote:
> Cold rolled is harder cause it is work hardened in the rolling.


For what it is worth, I don't know of any steel products that are "rolled"
cold.  The "proper" designation for the material is "CF" which stands for
Cold Finished, and the hot rolled material is first descaled and then drawn
through a die to the finished size just like wire, and becomes work hardened
in the process.

Once it is heated past critical temperature, there is absolutely no
difference from the "hot rolled" variety. I have forged many pieces of CF
steel up to 4" dia., and once it is hot it forges exactly the same. It only
acts kinky when you are trying to bend at a dull red, then the stiff spots
show up.

I have found that the quality of the cold finished bars tends to be inferior
to the hot rolled material, that is, I suspect the mill takes the bars that
are too ugly to sell in their "as rolled" condition, and sends them through
the cold finishing in the hope of making "sellable" product.

Tom Troszak