Hi all,

Sorry if this gets out there twice, but I don't think my first attempt
made it.

The question:

Has anyone ever heard of intentionally using a work hardening material,
such as so much of the stainless family, and actually adopting processes
to work-harden it, on purpose, for machine tooling? I understand that
this would be pretty much just a case-hardening, but for sliding surfaces,
when you are hardening primarily with wear resistance in mind, would you
need anything more than a case-harden? Has anyone ever heard of this
being a successful production model? Well, in particular, as a final
shaping step for machine tooling. Yes, I've heard of cold-rolled stock.

Some background:

I'm trying to develop products that will be either significantly better
than the competition's work at no more than what they charge, or something
to do the same ``job,'' whatever that job may be, every bit as well as
their product, at a much lower cost. The ideal, of course, would be to
offer something that works better, *AND* is significantly cheaper.

The objective is to fundamentally change the design of some ``gizmo''
(whatever it may be) to make it significantly easier to build, and thus,
cheaper to sell. The idea is NOT to do all the easy stuff that weasels
tend to look for like using cheaper, inferior materials, be cheap with
employees, etc., etc. No, I don't want to build junque, and I sure don't
want to have to have employees that need constant babysitting, and who
won't produce anything good unless they think they're being watched.

I want to build something of which I can be proud, and if I hire anyone,
I want to hire folks that will care deeply about doing good quality
work, and encourage them to do so with a paycheck in which *THEY*
can take pride. I want to take a product with an established market,
fundamentally redesign it to make it simpler, easier and thus, cheaper
to build, obtain the appropriate patents and start selling it.

After lots of false starts, well, maybe this latest one I've been working
on just might be the answer. Then again, it might get tossed onto the
scrap-heap of other ideas in my head. Still a little too soon to tell,
at the moment, but it sure does look promising.

The product:

I'm certainly not going to go into any detail on the design, but I think
I know how to build a wedge style quick-change tool post that I suspect
I may be able to sell for less than what I see even the cheapest piston
types go for. Hence the reason for this post: I figger, this is probably
a reasonable place to go for advice, as a lot of the experts are here,
besides, if this works out, y'all are gonna likely be the beneficiaries
of this new toy, so why not ask you folks to lend a hand, eh? :-)

The problem:

Material selection stinks! My father used to tell me that the most
difficult thing for any engineer to do was just choosing the material.
Although I never doubted his word on that, I'm now getting a wee-tiny
little taste of it. In trying make a tool that is both inexpensive and
of exceptional quality, material selection will, of course, play a huge
role, so I sure want to get it right the first time. The way I see it,
nothing says ``I believe in my product'' like one of those no questions
asked ``forever warranties'' such as is found with Zippo and the like.
I very much want to do that. In doing so, I certainly don't want to
see a bunch of parts coming back to me. Obviously, the only reason to
do such a thing is if you believe so strongly in your product that you
don't think you'll see a lot of parts coming back. The way I see it,
material selection for this tool comes down to (at least):

1) Strength: I don't want it to deform even under constant, heavy use.
2) Wear resistance: For obvious reasons.
3) Corrosion resistance: Even in nasty environments (i.e. coolant).
4) Processing cost: For obvious reasons.

Cost of material, I'm not really all that concerned about, believe it
or not. From what I can tell, that looks like it'll probably be just
about the least of my expenses in this endeavor. I'm far more worried
about how much it's going to cost to process whatever material I choose.

Strength, well, actually I suspect that's one of the least of the above
worries. I suspect that pretty much any steel of any reasonable quality
will probably be strong enough. Most of the strength will come from the
mass of this thing, I suspect, not so much from the steel selection, but
it is important enough to at least include it on my list of worries.

Now, some suggestions I've gotten are for either Ni-Cr-Mo or at least
Cr-Mo types (4340 or 4140, and such like so). Some disadvantages I see
there are that in order to really get the most out of them, they'd need
to be heat-treated. That just seems way too costly to me. Remember,
I want to offer exceptional quality at a really good price. I know I
can get these metals in various conditions, but it just seems to me like
this is something of a tradeoff: If I get it soft enough to machine at
all, even only with great difficulty, it seems like that's going to be
soft enough to allow more wear than I'd like. Further, I do believe
both of these are somewhat corrosion resistant, but are they enough
so that one could expect these things to stand up to coolant and time?
I even got a suggestion for O-2 (machines well, heat treats well were
the attributes named by the suggestor), but there again, to get the kind
of wear resistance I want out of it, it would have to be heat-treated, eh?

One of the things I've been thinking about is a good stainless. Most
(I know, not all, but most) of the stainless family doesn't heat treat
well at all, but it *DOES* work harden. That's normally considered a
bad thing, but I'm starting to wonder. In particular, if I understand
this right, a lot of this stuff work hardens particularly when cold
formed (rolled). I'm wondering if I could actually use this otherwise
detrimental quality to my advantage. I'm wondering if I should consider
cutting the parts a little over-size and running them through an eleventy
buhzillion ton rolly-squeezy-mashy machine for final forming. The way I
see it, if such an approach actually works, it could have some advantages:

1) I'd get to build myself a really cool rolly-squeezy-mashy machine, and
I'd get to watch it go.

2) Obviously, my corrosion worries would be pretty much over. Yeah, I
know, stainless really isn't guaranteed to be really stain-less, but hey,
I should be able to afford to (and, really, should expect to) replace at
least a few of these things. It should be pretty unlikely that I'd get a
lot of corrosion, no matter what form of nastiness someone's putting in
their coolant, in their misguided attempts to keep it from going foul.
At least I'd have the satisfaction of knowing that even though I have to
replace a tool post, well, they probably had to replace a whole lathe. :-)

3) I'd get to build myself a really cool rolly-squeezy-mashy machine, and
I'd get to watch it go.

4) Hardening without heat treatment. No fumes from whatever form of
nasty stuff you quench with (depending on the material chosen and effect
desired) to make people sick. None of the stuff slopping on the floor
waiting for someone to slip on and hurt themselves. Nobody looking over
my shoulder to see what I'm doing with the stuff, and above all, it would
*HAVE* to be cheaper to build and run a specialized rolly-squeezy-mashy
machine than a specialized heat-treat facility.

5) I'd get to build myself a really cool rolly-squeezy-mashy machine, and
I'd get to watch it go.

6) I'd think I'd have to worry about finish (while machining) a lot
less. If I'm gonna run my parts through that rolly-squeezy-mashy machine
after machining, it seems to me that thing is gonna put the finish on,
not my cutters. So, when my cutters start getting a little dull, and
the finish starts to get a little stinky, I just say to myself, ``huh,
I guess I'd better think about indexing those things around sometime in
the next week or so'' shrug and go back to turning the cranks.

7) I'd get to build myself a really cool rolly-squeezy-mashy machine, and
I'd get to watch it go.

Yeah, OK, so it's not perfect, either I'm sure. For starters, I have
no idea how hard I'd be able to get my sliding surfaces, or for that
matter, just how well that hardness will translate into wear resistance.
I know there's a correlation between hardness and wear resistance, but
I don't know if this process would really be good enough in that regard.
For that matter, I don't even know if it would necessarily be any better
than what I could get from some, say, condition medium 4340 without any
post-machining heat-treat.

I realize that my rolly-squeezy-mashy machine would probably not be the
end of the processing. Presumably, I'm not going to get the exact right
shape coming out of that thing, so I'd probably have to grind some after
that, too.

What about internal stresses? What are those going to do to my tool
posts? I sure don't want, 20 years from now, to hear a ``*BOINK*'' as
the first of my tools that I've been shipping for the last 20 years falls
to the floor in a buhzillion little pretzel shaped pieces. That would
be considered a bad thing, I believe.

Has anyone out there heard of doing such a thing successfully? I've been
scrubbing the Net, and all the references I find say something like
``unfortunately this material work-hardens...'' as if there is no possible
upside to that. Is that really so?

Is this just yet another bad idea grunted from my brain which needs to be
abandoned like so many of the other steaming mounds my brain has grunted
out over the years?

Anyone wanna offer support for some other materials and/or methods?

BTW, if anyone has pointers to exact dimensions for all (or any, really)
the various sizes of Aloris tool holders, I sure would appreciate hearing
about that, too. I've been seeking and not finding. I certainly want
to match their dimensions as they've become, pretty much, the defacto
standard, as far as I can tell.

Thanks,
tg.

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To reply by mail, remove all lower case letters in my return address
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One definition of an engineer is someone who can make something that
any damn fool can make, but the engineer can make it for less money.
The less money needs to include total cost over the life of the item.

Stainless may be a great choice for whatever it is you want to make,
but it may also not be the right choice. If the stainless costs 50%
more for the material that may not be important, but if it raises the
cost of manufacturing by 100 % , it may be the wrong choice.

That said and not knowing what you want to make, have a look at 5-15 ph
stainless. It does take a heat treat to achieve its best qualities,
but the heat treat is very simple. Basically raise it up to something
like 1000 C ( might be 900 C ), hold it there for a short time, and let
it cool.
Easily done in a ceramics kiln.


Dan

wrote:
One definition of an engineer is someone who can make something that
any damn fool can make, but the engineer can make it for less money.

Yup, that's the goal.

The less money needs to include total cost over the life of the item.

That's *REALLY* the goal.

Stainless may be a great choice for whatever it is you want to make,
but it may also not be the right choice. If the stainless costs 50%
more for the material that may not be important, but if it raises the
cost of manufacturing by 100 % , it may be the wrong choice.

That said and not knowing what you want to make,

I'm sorry. That post was *WAY* too long. Didn't even realize how long
it was myself until I saw it in my news reader. Sorry.

It was in there, but it's no wonder you missed it amongst all the clutter.
I want to make a tool post. In particular a tool post that'll last as
close as I can get to forever. Don't want it to rust, even with coolant.
Don't want it to wear, even under heavy use. Don't want it to deform,
even when somewhat abused. You know, all the standard miracles. :-)

have a look at 5-15 ph
stainless.

Is there a more common name for this? Although I don't claim to have
reviewed them all, I've looked at a lot of them, and this doesn't look
familiar...

It does take a heat treat to achieve its best qualities,
but the heat treat is very simple. Basically raise it up to something
like 1000 C ( might be 900 C ), hold it there for a short time, and let
it cool.
Easily done in a ceramics kiln.

Well, still sounds costly, but I'll at least look into it. Thanks.


Dan


Thanks,
tg.

--
To reply by mail, remove all lower case letters in my return address
).

You will have an easier time finding it if you use the correct name
15-5 ph.
Sorry about that. There is also other grades of Precipitation
Hardening ( PH ) stainless. 17-4 is one of them.

I was also wrong about the heat treat. 900 degrees F ( not C ) for
an hour and air cool is a common heat treat. Typically gets 200 ksi
and C 46 hardness ( from AK steel web site ).

I also did a bit more looking. Custom 450 stainless from Carpenter
Technology is essentially the same steel.


Dan

wrote:
You will have an easier time finding it if you use the correct name
15-5 ph.
Sorry about that.

You don't have to be sorry for *MY* ignorance. I just hadn't seen that
yet, so I didn't know that was its proper name. Thank you for cluing
me in.

There is also other grades of Precipitation
Hardening ( PH ) stainless. 17-4 is one of them.

I was also wrong about the heat treat. 900 degrees F ( not C ) for
an hour and air cool is a common heat treat. Typically gets 200 ksi
and C 46 hardness ( from AK steel web site ).

Wow, thanks a bunch for looking into that for me. I really appreciate
that. Although even 900F does sound a lot better, and the fact that
it's air hardened sounds very attractive, boy, it still sounds like it
could be expensive. I haven't run any numbers yet, just a SWAG.

However, the lower temperature sounds a lot cheaper, but then again, it
has to be held there for an hour. The air quench also makes it sound a
lot more attractive than oil, or worse yet, cyanide (or other forms of
OSHA and environmentalist fodder). Certainly don't think I like water
quench materials. Much too much distortion, from what I hear.

I also did a bit more looking. Custom 450 stainless from Carpenter
Technology is essentially the same steel.

Ah. Thank you. That was another one recommended in this thread.

Dan

Thank you for all the help. Looks like I've got some homework to go do
now, but at least I've also got some direction.

Thanks,
tg.

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To reply by mail, remove all lower case letters in my return address
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