My local metal supplier sell Al tooling plate remnants at about half the
cost of their 6061-T6. It comes in thickness up to about 1" and has a
very good surface finish and dimension. I am about to use some to make
various parts, none of which have structural consideration.
I don't know much about the properties of "tooling plate". That it is
used for and are there any caveats from making small, nonstructural
parts out of it? Any and all info regarding "tooling plate" is appreciated.
Its gritty, grainy shit that has very little fatigue or tensile strength and
tapped threads will strip and or pull out of it in a heartbeat.
It machines okay at lower speeds with kerosene or wd40 and that sorta stuff,
I havent never had real good luck with it myself using the water based
coolants and high speeds.
Cutting tee slots, narrow slits and that sorta thing in it can be an ass
puckering experience what with all the little popping sounds and whatnot
happening at seemingly random moments.
A reamed or drilled hole is very likely to go quite a bit oversize if theres
any runout at the chuck....
If you drop it on the floor, its most likely GONNA get a big dent in it, or
perhaps even break because its kinda brittle too......
( Im exaggerating maybe just a bit with most of the above, but I think you
should get my drift )
Now on the other hand, its fairly stable and is typically supplied to pretty
accurate tolerances as to thickness, parrallelism and flatness.
I've used a fair amount of tooling plate through the years and can say that
I agree with PrecisionMachinisT. It's primary purpose is as its name
implies, for tooling., where flatness and parallelism is a factor. To
protect the surface, it normally comes papered. It is typically cast and
Blanchard ground, and quite stable, although lacking in tensile strength and
machinability. Think cast gray iron and you get the idea, only gummy.
Cuts fairly well with lots of positive rake and HSS. It tends to leave a
poor finish, although when reaming it can come out quite nice if the reamer
cuts size. Sort of burnishes the hole.
Would I use it for making anything beyond a base plate for a tool?
Absolutely not! I think you'd be quite unhappy machining it, and with
the end results, especially if you're concerned with aesthetics.
If you want some killer good machining aluminum, try some 2024T351 or
7075-T6. You'll love how they cut, and the finishes will be much better
that with tooling plate. 7075 cuts prettier than 2024, which tends to
cut with a dull surface finish, although quite smooth. Neither of these
alloys can be welded.
One added note about 2024. Due to the copper in the material it tends to
anodize poorly. At least in a black color. It will have a patchy
appearance. I'm not too sure about 7075, but tooling plate also anodizes
poorly, since it is a cast product. At least what we use, is cast. I
respectfully disagree with Harold and Sam about the machining though. We
use a large amount of Mic 6 (Alcoa product) tooling plate for our tooling
(none for production parts) and special machinery and haven't had any
particular problems machining. It's all used in milling and we use a mist
coolant (along with brush on oil) and do a lot of precision machining with
no problems. We normally do not anodize, and the finish of the machined
surfaces are not of any particular concern. We drill, ream, bore and mill
to close tolerances all the time using off-the-shelf cutting tools. Mostly
cobalt, but also some carbide. The material is less ductile than the
wrought aluminums, but unless you're working with very small, fine threads I
doubt it would be a problem. The main thing to keep in mind is, what's the
application and how's it going to be used? Though the finish is, like
Harold said, similar to what you'll get with gray cast iron. Smooth, but
grainey without a nice aluminum shine.
Who is your local distributor? We use lots of the material in 1/4", 1/2"
and 3/4". Maybe we'll take some off of his hands <g>. We are paying
anywhere from $5.14 to $7.72 per lb. for cut sizes from a Portland
distributor. If you can get it for less than 6061-T6 I'd go for it! If
your distributor is anywhere on the west coast I think I'd buy some at those
Thanks, all, for advice. Most of the parts I am making are "plate like"
with the thickness being the same as the tooling plate I have. I'm going
to try to machine it (mostly drilling and boring), knowing full well
that it may be less than satisfying. I'll get some other alloy for
complex 3D parts.
Industrial Metal Supply in Burbank, CA. $1.29/lb for tooling plate
remnants. Biggest pieces are about 8" x 12". I'm guessing that this is
too small for most typical applications or they wouldn't be selling it
cheap. It's plenty big for my parts.
I made a wave guide assembly from 2024 for Univac numerous times. It
required clear anodizing, which worked exceedingly well. The anodizing
process used makes a world of difference. They were anodized to a Mil spec
in this instance, considering it was defense work. Which Mil spec. I can't
say, for this was more than 20 years ago. Of all the aluminum grades, I
prefer machining this one, although the surface finish never shines.
It anodizes and responds to dying as well as, if not better than, 6061 does.
It also machines better, with the highest tensile strength of all aluminum
alloys, at least in the T6 condition.
It's not that there's exactly problems, although it tends to stick to the
tip of your tool, but more about knowing that other grades of aluminum
machine far better, so by comparrison it's not fun to work. It's not even
fun to file, as you may recall. I've never seen any material clog a file
the way tooling plate does. As you implied, it works fine for someone that
has machining experience and knows what to do about the little irritating
things it does, very unlike the rest of the recommended machinable grades of
aluminum. I have a small piece of 1" that has kicked around my shop for
well over 30 years. I could have used it for small projects countless
times, but went out of my way to avoid doing so because it simply doesn't
machine as nicely as other alloys. I guess what I was suggesting is that
making parts from it would add enough problems to the operation for a guy
that may not be up to speed in machining that it wouldn't be worth the
savings to go through the frustration of trying to make things look good.
The aesthetics thing.
I've made no tooling plate purchases since closing the doors on my
commercial business. It would have to be damned cheap before I got
interested, if even then. YMMV.
I agree Harold, 2024 is a great machining material, and very strong. Here's
a fairly quick story about 2024 alum. About 1988 I was working at a company
in No. Nevada that manufactures microchip probing machines. These machines
were made from a large number of machined components which needed black
anodizing since they were cosmetic in most cases. No high strength
requirements. My title at that time was Production Engineering Manager and
as such I thought I'd try and convince the G.M. that we didn't need to make
all the machined parts from 2024. I did an analysis and found that the
company could save a huge amount of money if they'd change to 6061-T6.
Well, they changed and everyone thought it was a great idea...except the
guys in the shop! They weren't too happy. Since I had been the Shop
Manager for two years I was able to sooth most of the ruffled feathers <g>.
Since black anodizing was very important, the 6061 helped in this area too.
The interest part of the story is how they came about using nothing except
2024 for all the aluminum requirements. The company had started about 10
years earlier in the San Diego area. Since they were small and struggling
the owner would buy his material at a Navy surplus sales yard. Well, most
of the military aluminum is going to be 2024 (at least that's what he got)
and they just never thought to try anything else. At that time there was
somewhere around a 30% to 50% difference in cost.
According to my references, 500 (magnesium) and 700 series (zinc alloyed)
anodize the best. 200 (copper) is middle around, and 300 series, which
casts the best, also anodizes the worst (a 4 out of 5 rating).
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