Subject pretty much says it all: What can one expect to pay for various
forms of heat treatment (for hardening, not annealing)? I've been under
the assumption that any kind of heat-treat is pretty spendy, so I've
been trying to pick materials that can get by without, but some folks
are telling me it ain't so bad. I can find no pointers on price, though.
Not so bad to one guy could be a back breaker to another...
I know different materials are going to require different procedures,
so I would expect the costs to vary. However, does anyone have have any
rules of thumb to get me in the ballpark of what I might expect for at
least a few of the various procedures? Knowing the price differences
in the treatment types would also help me in material selection.
For a general idea, think a cube of steel about 3.5" on a side. That
should be about the right ballpark. Probably doing these in respectable
quantity, like maybe a few hundred in a squirt. Not vast quantity, but
Heat treating doesn't have to be expensive unless you want to rent a
high priced brain. you can do small tempering with a gas burner or
charcoal grill. Larger items are done with open forge fires or
furnaces, which runs up the price.
Tempering theory is simple: Quench from a red heat to harden, using oil
or water as a coolant.
Draw [read soften] the temper by low, uniform heat between 250 and 600
Degrees F. The surface of the polished steel will indicate the proper
draw point by the color of the oxide formed: straw yellow for razors,
gravers & other very hard [but brittle] tools. Ruby red for cutlery and
cold chisels. dark red to purple for high impact tools like axes and
pick points. Deep purple is spring temper. Black is annealed and soft
That is the bare bones basics of tempering steel. Different alloys have
their own characteristics, so there's an infinite array of
"The other Thomas Gardner"
I think my heat treating costs are cheaper than the shipping to the heat
treater so I drive the 2 miles. I'll do small, one-offs in the shop. Like
everything else, supply and demand...are there a few firms in competition
around the neighborhood? Don't do it at home, it's another job that will
steal part of your life and cost WAY more than you think. Are these parts
for your "time machine" design? Get to work on the motor!!!! ...or you
will be labeled "The Prince of Procrastination" (I'm the KING)
Give a yellow pages call, or try the closest Thyssen Marathon. They
will give you prices, but ask LOTS of questions. If you waive damage
claims, are willing to wait, and your stuff is small enough to go in
with a big companies load, and it's not some critical material, prices
may well be below $10
On 13 Oct 2005 12:41:37 GMT,
snipped-for-privacy@ElectEngrngCompSci.CaseWesResUniv.EDU (The other Thomas
I've dealt with at least a couple flavors of heat treating outfits: We
used a small tool and die orientated place that would do all of our
special cutters, punch dies, etc. They did all of their work in small
ovens, fully instrumented, dealt with tool alloys all the time. Just
specify the alloy and the Rockwell and you got it back two days later.
It's been a few years but IIRC they had a minimum charge of about $35 to
run one part or small group of parts. More weight meant longer time in
the oven and a few $$ more.
The other shops were high volume production places. We also did one job
that had 16 4130 frames mounted in a rack that went into a 8' diameter
by 16' deep pit furnace. 3 pits in a row, (high temp, quench, temper)
with an overhead crane. $500 for the lot.
These same shops had all sorts of other equipment: conveyor furnaces,
vacumn furnaces, batch furnaces, etc. Pricing is dependent on the
handling required (manual placement vs conveyor), special treatment
(nitrogen atmosphere for nitriding), and length of time in the furnace
(thick part need a longer soak time)
I'm sure that you can get some competitive bids once you get to 100 at a
time. I'd toss out a SWAG number but you really didn't give enough
detail on the part.
Keep in mind that if your "cube" is anyere near solid (eg a block with a
few holes drilled in it), heat treating gets real fussy. It takes a
longer time to get the whole part up to temp, quenching evenly is
difficult. And then there is the warpage and shrinkage problems. If you
just call up a volume place and dont have ready answers about what
tolerances you can live with, they will give you the run around.
The other Thomas Gardner wrote:
I figgered that much. I'm definitely thinking ``close to suppliers''
when I go looking for my location. So, if you've got, say, 1000 lbs or
so of stuff to go off to the treater. Say you're after a case harden.
Medium depth. What do you expect to be reasonable? Ball park?
Yeah, me too. For my own stuff. I'd prefer to treat customers with a
little more respect than that, though. :-)
Ain't found 'em yet. You know how that goes: You call an industrial
service company on something you're not sure about and you get run
around if you're lucky. Ignored, primarily, and if you can talk them
into doing business with you later they generally charge you 10X...
No kiddin. That's why I'm tryin' to put feelers out.
Yup. Although most folks call it a tool post, that's pretty much what
I'm hoping it might turn into: A time machine.
After giving up on my last time machine and going back to the motor
work again, I later turned back to the time-machine theory (but with
different specifics): Make something to sell that won't consume every
waking moment so you have at least a little time for motor research.
This QCTP just might do that for me. Still in the research stages.
Ain't even hammered down the material yet. The old man used to tell
me that was the most difficult part of any project. Although I didn't
doubt him, well, now I'm really tasting that for myself.
The motor hit a bit of a snag (actually several, but I worked through all
but one). When I finally figured out how to do more of the calculations
with the latest design with all the other snags worked out, I found that
it is not too useful in the smaller sizes. My target market was going to
be to start with toys (RC cars and whatnot). You know, a niche group.
I'm having to go back and redesign for the larger sizes now (no less
than, say, 1 or maybe even 3 HP minimum). I'm thinkin' the new niche
market might be home-shop folks who want to convert their machinery from
3 phase to single phase on the cheapy-cheap. Any ideas where I might
find such folks? :-)
Actually, with such a restriction, I'm honestly starting to doubt if
this is even worth pursuing any more. Just like that. 15 years down
Anyway, I've had to go so far back on the drawing board, well, I think
I'm looking at a blank sheet again. I'm still going to build the one
for which I have the plans and steel. I need to make sure that my calcs
be right. Could be I'm off by a few orders of magnitude (and I'm off
that far IN TH RIGHT DIRECTION). It's been known to happen before.
Yeah, well, more scatter-brain than anything else. Just have too many
projects underway, and always dreaming up new ones.
This is excellent info. Thanks.
That'll probably be close to my situation, I believe. Having a hard
time picturing the volume, though. You recall approximate thicknesses
on your parts? What kind of tonnage would you guess on that?
That's exactly what I'm hoping for.
Well, a 3.5" per side cube is pretty much it. Of course it's got
dovetails cut on 2 faces (this is a QC lathe toolpost). There are some
other bits taken out hither and yon, but mostly, it's really pretty
close to a solid cube. If you'd care to SWAG that, you *SURE* wouldn't
hear complaints from me. :-)
Yeah, well, I assume I'll have to do some grinding when it comes back.
Another reason why I was (and really, still am) hoping to pick a
material that would be wear resistant enough for the job even without
I've been reading like crazy trying to educate myself, and somehow or
another, I seem to have gotten the impression that warpage and shrinkage
problems are worse, the faster the quench process required for the
material. So, for instance, a water quench will warp parts far worse
than an oil quench. Is that true? If so, what about something that can
be air hardened? Wouldn't that be slower still, and therefore deform
parts even less? Of course, I also seem to recall that big honking thick
parts like the ones I'm talking about, would have to be oil quenched,
even with air hardening materials chosen (part just won't cool down fast
enough in air if it's too thick). Is that something I just imagined?
Exactly! Trying to find my clue now. I'd rather find it in a newsgroup
than with a dealer where it could cost me oh, so dearly, in oh, so many
Thank you so much for your help. I do appreciate it.
"The other Thomas Gardner"
A place that where I work uses a lot (near Hartford Ct.) charges $0.65/lb or
$65.00 min. to harden and temper alloy or tool steel. Carborizing and PH
stainless grades are I think $0.75/lb or $75. min.
Indeed, I was leaning toward a case harden anyway.
Artemia Sal> On Fri, 14 Oct 2005 02:05:31 +0000, The other Thomas Gardner wrote: >
What grade(s) did you have in mind with that statement? The less exotic
I can get on the processing the better, in my book. The less deformation,
the less post treat processing, all that, the better.
Thanks for the input.
Wow! Paul! Thanks a BOATLOAD! That's exactly what I was looking for.
I know it won't be exact, but it gives me something to go by. At least
this way I'll know if someone is trying to give me short end of the stick
or not. I just didn't know what to call reasonable, or what to budget
for. Now I do.
It seems that I may have been wrong about this after all. I could
have sworn that I'd read something online about using Kasenit and
not having to quench. I even remember being impressed by that because
it seemed like that would lessen the chance of the parts warping.
Now, as I attempt to look that reference up, I can't seem to find it,
and most discussions of using Kasenit talk about quenching as part
of the process. Disappointing.
So I apologize if I am wrong on that. I should've checked my facts
Egads. How embarrassing: I'm so ignorant, I thought you were just making
the word Kasenit up (i.e. ``casing it doesn't require quench...''). Never
dawned on me that was an actual product name. Obviously, that's something
I hadn't run across yet.
Tommy ``big doofus'' Gardner.
Artemia Sal> On Fri, 14 Oct 2005 15:50:41 +0000, The other Thomas Gardner wrote: >
"The other Thomas Gardner"
Kasenit turns the surface of plain steel or certain low-alloy steels
designed for case-hardening into very high-carbon steel -- plain
high-carbon, if you start with plain carbon steel. It works by diffusing
carbon into the steel, from the outside in. Thin cases may be only a couple
of thousanths of an inch thick. It's possible to produce thicker cases using
special methods, and some industrial process can produce a 1/4-inch-thick
case or even more.
Hardening any steel by martensite conversion (which is the hardening process
we're talking about here) requires a rapid quench through a certain critical
range of temperatures. Different alloys require different quench rates.
Plain high-carbon steel requires the fastest rate of all, on the order of a
few seconds, which is why it typically is quenched in plain water or brine.
Air-hardening steel, as the name implies, is at the other end of the scale:
the quench rate can approach an hour. But that's not case-hardening with
Kasenit. That's through-hardening of a special alloy made for slow quench
If you want maximum hardness from a thin case in steel, such as one you get
with Kasenit, you have to use carbon-steel quenching rates and methods. That
usually means a water quench. There are some rare exceptions, such as
extremely thin blades or very large, thick masses of steel or iron that you
surface-heat with a flame or other means (thus, flame-hardened lathe beds),
which self-quench when you heat them quickly and then take the flame away.
But think in terms of water quench if you want a really hard case, on the
order of Rc 62 or higher, for any normal application.
What you probably read is that you don't have to *temper* a case the way you
do with through-hardened steel. That's generally true, if the case is thin
and if you aren't going to beat it with a hammer. But you then have a
brittle, if extremely hard case -- perhaps Rc 70. It makes a great wear
surface for bearings of many kinds but you wouldn't want to try it on a very
thin section that had to flex, or it would crack.