[TheForge] Superquench/hardening power hammer dies

[David E. Smucker]

The parts hardened and measured by Otto Bacon had a cross section of 1/2 x 
1/2 with a Rc 50.  This is not the same as a piece the size of a hammer die. 
Even if it has a very hard surface, (which is unlikely, but I haven't made 
one and measured it.) the core of the A36 die will not be hard, or tough, 
and not perform the way a tool steel die will.  Keep in mind that it is not 
the quench medium that gives resultant hardness -- it is the quench rate and 
make up of the steel.  A small part with a fast quench medium is one 
thing -- a larger part with the same medium and therefore a slower quench 
will not give the same performance.  Very thin sections of a water hardening 
steel (1095, W1) will quench to high hardness in still air, but not a hammer 
die. You can try this with spring wire for example.

Even 1095 (W1) quenched in brine will only have a case hardness of about 
0.60 inches.  It will have a good tough core because it has 95 points of 
carbon.  This makes it very good for many tooling applications.  If we want 
a greater depth of hardness then we need to move to the alloy steels with 
the addition of chrome, moly etc. etc.

Dave Smucker
----- Original Message ----- 
From: "Schade" <schade at acegroup.cc>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Wednesday, December 29, 2004 8:01 PM
Subject: Re: [TheForge] Superquench/hardening power hammer dies


>
> On Dec 29, 2004, at 5:03 PM, David E. Smucker wrote:
>
>>   A36 hardened in superquench is not tool steel.  It is just A36 about as 
>> damn hard as you can get it.
>
>
> That's good enough for me.
>
> Those that have tested it get 50 on the Rockwell "C" scale as in the 
> article in the current Home Shop Machinist by Otto Bacon. 50 RCH should 
> make a fine 25lber die.
>
> Bob
>
>
>
>
>
>
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