[TheForge] 4140 heat treat

Thu Nov 13 18:39:00 2003

For 4140 hammers some folks like a running water quench of the working face
followed by a temper.

What I preferred is to take the hammer head to critical temperature 1575 F
and hold for about 5 minutes  -- this temperature is a little bit above not
magnetic but not much and then quench in oil with lots of motion until cool
to at least 150 F.  I then wash the hammer head to remove most of the oil
(real hot water) and temper right away in "the wife's" oven at 350 F for one
hour.  Let it slow cool to room temperature.  This will give a hardness of
53 to 54 Rockwell C.  If you want it softer and tougher a high tempering
temperature will yield both -- 400 F about 52 - 53 Rc and 450F about 50 - 51
Rc.

Don't worry if you hammer comes out of the oven with a "blue" color.  These
colors are not the same as the fast temper colors if just heating the item
because there is a lot to time for the surface oxide to form which give the
color.

This is what I use, other will use a somewhat different method.

Dave Smucker

----- Original Message ----- 
From: "kim george" <[email protected]>
To: <[email protected]>
Sent: Thursday, November 13, 2003 5:10 PM
Subject: [TheForge] 4140 heat treat

> I got a new computer and the answers to this question got lost. I'm making
> some hammers (with out a power hammer, yeah, i'm a glutton for punishment)
> and hopefully will be able to heat treat before my arm falls off. So
what's
> the process?
>
> Kim George
>
>        "Why for you burry me in cold,cold ground?" Taz
>
>
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