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

[Bruce .]

Re: Accuracy.
I was speaking only of accuracy of diameter.  E.g., a 1/4" hole to be
accurate should be 0.250".  For my purposes, I could tolerate anything from
maybe 0.245" to 0.260", depending upon my exact purpose.

The accuracy that would be needed would be centralizing both the die and
the punch, and getting the right clearance between them.


Bruce
NJ

On Fri, Dec 2, 2016 at 1:41 PM, Charles <xlch58 at swbell.net> wrote:

> I would second the suggestion.  4140 is ordinance steel, it is not
> necessarily very hard, it is meant to be tough.  I use it for receivers.
> If you are using bolts or threaded rods, in general unless they are from a
> supplier that is certifying them, there is no guarantee they are.   I would
> also comment on the accuracy statement.  The thinner the metal you are
> punching, the more accurate the fit you need between the punch and anvil.
> Charles
>
>
>       From: jerry Frost <akfrosty at mtaonline.net>
>  To: 'Blacksmithing List Sponsored by ABANA' <theforge at mailman.qth.net>
>  Sent: Friday, December 2, 2016 1:00 AM
>  Subject: Re: [TheForge] Question about the steel and treatment needed for
> small punches and dies
>
> 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
>
>
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