[TheForge] Question about the steel and treatment needed for small punches and dies

[jerry Frost]

You can buy die sets for Roper Witney tools and not just punch sets.

If you really want to make them I'd use O1 tool steel and not play the
guessing game of what company X made their grade 8 bolts from on that run. 

Things like bolts are made to performance specifications not analysis
specifications. So long as they're strong enough, have the correct range of
deflection, shear, etc. they can be called whatever grade is being made.

It's the same thing we're running into buying "mild" steel. There's a big
difference between 1018 mild steel and A-36 mild steel. 1018 must fall
within the analytical range specified as 1018. Where A-36 only has to meet
performance specs say minimum tensile strength of 35,000psi and so on. It
can exceed specs without problem but there's no predicting what it was made
from.

Anyway, were I going to make a set of punches rather than buy a set I'd ask
Roper Witney what theirs are made from and if they won't tell I'd go with
O-1. the higher carbon or higher alloy steels the trickier the heat treat
gets.

Frosty

-----Original Message-----
From: TheForge [mailto:theforge-bounces at mailman.qth.net] On Behalf Of Bruce
.
Sent: Thursday, December 1, 2016 3:53 PM
To: Blacksmithing List Sponsored by ABANA
Subject: [TheForge] Question about the steel and treatment needed for small
punches and dies

I have a few hand-lever Whitney and Roper Whitney punches, but lack a
complete set of dies.  However, I do have a lathe, and I was wondering about
making these parts myself.

Dies:
What I was thinking was to anneal some grade-8 threaded rod, then drill it
to size for the die, harden and temper it.  (The tight specs possible with
boring not really needed here, as I'm only proposing to punch sheet metal
with the resulting punch & die pairs.)

My choice of this material is due to its availability threaded.  In
principal I could thread a rod myself, but I have little experience doing so
and would hate to take the time and effort.  I reckon that there's enough
mass in the die that the exact alloy I use might not matter much.

Grade 8 bolts & all-thread are apparently to ASTM B7 spec, which, I read, is
something like 4140.  So, my question is how to anneal and how to harden &
temper.  I do have a small electric furnace and an appropriate pyrometer if
exacting conditions are needed, but I wouldn't count on being able to hold
TOO exact.  (I'm over my head here, but do have a Metals Handbook if it
comes to that.  It's a lot easier to ask here first.)

Punches:
Similarly, I would take some appropriate steel rod (see
https://www.mcmaster.com/#standard-steel-rods/=15aac3v ) and machine it to a
compatable size for the die I make.  The question here is WHICH alloy would
be most suitable?  And how to anneal (if necessary), harden and temper it.
(Again, exact diameters of the resulting holes are not critical, but the
clearance between punch and die is.  I'd use my Machinery's Handbook for
reference.)

Any pointers would be welcome.  I don't see myself starting this very soon,
but it might be a nice over-the-winter project.

Bruce
NJ