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Work Hardening steel


Hello: I just purchased tool steel from Bonny Doon for die making. I
need to harden the steel after my die is made. How do I go about doing
so? dede


Go to the Bonneydoone web site:
Look in the learn section If you have more questions go to the forum.
The expert is there all the time (Dar Shelton)


I need more to answer your question. Is the tool steel
air, oil, or water hardened? Each type has different hardening &
tempering procedures. All tool steels must be tempered after
hardening. Will be glad to give you exact details. -Leroy


Dede The actual heat treat depends on the type of tool steel you
have. In general, though, you will have to heat it to a temperature of
approximately 1500 - 1600 F and rapidly cool it to room temperature.
Whether you can air cool it or have to quench in oil is determined by
the type. At this point, the steel will be hard and brittle and will
need to be tempered. This consists of heating the piece to
approximately 300 to 500 F and air cooling. Again, the actual process
will depend on the type of steel you have.

Hope this helps.


DeDe You should definitely refer to the supplier (In this case Lee
Marshal of Bonne Doon) about how to harden a particular steel, since
they vary.



If you want the “truth” it is much easier to NOT cut your own and get
in touch with Dave Shelton, Sheltec, in Albuquerque, NM. He has cut
and hardened all my dies, and even tho I know how to do it… I don’t
want to and don’t have the time. Dave is super good. I highly
recommend him. I used to have the ‘formula’, but it is currently in
my ‘dungeon’… and I doubt he will give you this ‘secret’. Prehaps
someone else will. good luck, Red


dede, What grade of tool steel do you have, A-2, D-2, S-7…?? An old
shop practice, but it works. As always practice with a scrap piece,
first. You’ll need a torch that can put out some heat, if the work
piece is small and thin, thin to me is under 1/4". It may warp from
the heat, lay work piece flat on a nonflammable surface, like a large
piece of steel from the scrap yard, both work piece and what ever
it’s laying on are going to get very, very hot. Start with torch heat
applied to the center of work piece. Try not to place torch flame
directly on your cutting edges, as they may deform or melt, get close
and let the steel transfer the heat to the edges. Heat with a torch
till entire piece is “bright orange” keep your torch moving.
Depending on steel grade this temp will be around 1550F. Important,
after work piece cool’s down to where you can touch it without being
burned, think before you touch, please. This will be around 110F, but
not ice cold, place steel in an oven heat to 400F for 1-2 hours to
stress relieve steel, make’s it not so brittle. In a non-critical area
do the file test, if a file cannot cut into the work piece it’s hard,
if it cuts into the steel it’s not hard. Best of luck, Kevin


Leroy, the most important thing about using oil to harden the steel
is: Be sure to do it outside and have a cover ready, sometimes the
oil catches fire! Susan


DeDe A Book that I Most Highly recomended is " THE MAKING OF TOOLS "
by Alexander G. Weygers . I S B N - 0442-29360-7 A product for
casehardening mild steel is called " Casenite " . You just dip the
heated end of a mild steel tool into it and heat to red heat several
times, then quench and temper. It is moderately priced, not
siginicantly toxic, and can be purchased at any larger welding shop.
I am a Journeyman Millwright. I make some of the tools I can not buy
or can not afford . Buy the Book, Walk the walk, Talk the talk, and be
beholden to no curmudegon . Robert L.Powell


Heat the tool to a dull red and slowly cool it in air. Next sand the
working end to show clean metal. Then reheat only the working end in a
low flame until iridescent colors start to show up and crawl up the
tool. When you get a second order yellow at the tip, this is the
correct temper for general metal work. Now quickly quench the tool in
your coolant to “set” the temper. When the color at the tip turns
blue, you have the temper of spring steel and this is generally too
hard and brittle for iron work. This was from instruction in a 7th
grade shop class many years ago. Unfortunately, I forgot most of what
else the instructor was teaching, My attention being elsewhere.
Will Estavillo,