Using a drawplate or for that matter the square side of your durston
mill, to change the shape of this type of chain from when its
assembled to a square section, is not the best way to do it.
As anyone knows a mill and/or draw plate will make metal square.
the problem is it also becomes not only thinner, BUT also longer.
What one needs is a method to make it square without it getting
This can be done by either hammering it into a square depression in
a block of steel, or much better still a milled square slot in said
hardened steel block with a steel punch to match the width if the
slot. Aligned to each other in a fly press. I have various sized
slots for different widths in one block.
If you dont have one of these then a hand held one will do at a
However any serious hammering needs the proper support for metal die
blocks. A bench block will not do.
Get yourself a proper leg vice on a strong bench. Its the way to go
for this type of forging.
I do a lot of metal reshaping from round to a lot of other shapes
and find its been worth the investment to make the tools to do this
job Its quick, accurate, and repeatable.
As for making square section draw plates, this is usually done by
drilling the said steel when its soft, then with a hardened steel
tapered square sectioned punch ,drive this punch into the said
various sized drilled holes to various depths to change the holes to
square. then harden and polish up.
Its not easy to drill square holes.