High Density Metal?

I'm just planning my next project which calls for the use of High Density Metal, which has a specific gravity of 17 and is apparently tough to
machine. It's used as counterbalance weights in a crankshaft web. The weights will be 6mm diameter bullets inserted into the crank web.
Anyone know of a current supplier, Google isn't my friend on this one.
Thanks
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Density
to
The
one.
Well Uranium has a density of about 19, Gold 19.3 and lead about 11.3 so I reckon you are looking for an alloy
AWEM
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Here are the possibilities (g/cm^2, or specific gravity):
gold (Au) 19.3 iridium (Ir) 22.5 osmium (Os) 22.5 platinum (Pt) 21.5 plutonium (Pu) 19.7 rhenium (Re) 20.8 tantalum (Ta) 16.4 tungsten (W) 19.3 uranium (U) 19.1
Weeding out the obviously unsuitable, on grounds of extreme price (Au, Ir, Pt, Re), huge toxicity (Pu, Os) or radioactivity (Pu, U) that leaves Ta and W (tungsten).
ISTR that back in the 1970s someone made working railway locos at about 1/480 scale using solid tungsten bodies (for adhesion). If I were you, that would be my first choice, it is available, though probably not cheap. Both W and Ta would be tough to machine; Ta seems to best meet the description you give.
BTW, no realistic hope of casting either of these metals at home - melting points are 3017 deg C (Ta) and 3422 deg C (W).
Also, as Malcolm suggests, try tungsten carbide (though you would have to use a cylindrical grinder to turn it to size if you can't get the right diameter).
I know this does not answer your question on suppliers, but with the correct name(s) you can now search again.
David
--
David Littlewood

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My tungsten carbide gauge blocks have an SG of around 17, I believe. They certainly look like metal, and they conduct electricity.
--
M Stewart
Milton Keynes, UK
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Steve W wrote:

> Mallory metal?
Tom
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Posted via a free Usenet account from http://www.teranews.com


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Steve W wrote:

I don't know what "High Density Metal" is - but a high tungsten Elkonite (tungsten/copper alloy) will approach a sg of 17.
Anything other than high tungsten alloys with that sort of density will be very expensive - talking cubic money here.
-- Peter Fairbrother
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I suggest you Google for Steve Smith at Vibration Free. Specialists in crankshaft balancing including tungsten alloy heavy metal inserts for increasing counter balance mass.
--
Dave Baker - Puma Race Engines



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wrote:

Trog round to your local machine shop and ask nicely for some broken tungsten mills/drills.
We've only got diddy pcb drill sizes unfortunately.
Peter -- Peter A Forbes Prepair Ltd, Rushden, UK snipped-for-privacy@easynet.co.uk http://www.prepair.co.uk
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Looks like the economic option to me, the SG is about 14.5 from google so pretty close.
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wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item 0136230194
Nice bloke, just off Aston Church Road in Nechels/Washwood Heath, Birmingham. I was thinking of taking this off his hands, but you may have a more immediate use for it.
Mark Rand RTFM
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I think theres a material with a trade name like densamet
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Steve W wrote:

Probably the cheapest and best source for these "bullets" would be the shanks of solid carbide end mills.
Expensive as heck new, quite reduced in price once the cutty bit at the thin end is on the shop floor.
Scrap carbide is worth about $6 or$7 a pound in the US. Most machine shops keep them (or at least, many that I have knowledge of).
Another potential source is a welders supply outfit. Tungsten electrodes for TIG welding come in large sizes. IIRC the largest we have at work are 3/16", but I think they are available larger.
Carbide rod is used as a wear element on road maintenance equipment like graders and excavating equipment. A shop that does heavy equipment maintenance nay be able to set you up with a small section.
6mm would be about at the upper limit of diameters for tungsten dart bodies. A games supply shop may have a few mismatched dart heads that you could buy cheap(ish).
Some ideas, anyway.
Cheers Trevor Jones
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Steve W wrote:

You should google with "densimet"
Nick
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Steve W Wrote: > I'm just planning my next project which calls for the use of High > Density

Wow what a coincidence, I just found a billet of Elkonite with a measured density of 16.986! It's 1.989" OD by 1.165" long/thick. It cost about $350-400It's machinable too. Machines like cast iron. I believe it's 90% tungsten the balance copper and nickel. I'm going to list it on ebay unless you want to buy it. It is very expensive though for just a counter weight. Your choice. Thank you, Ken
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Google didn't seem to have any problem for me at least. Just stuck "tungsten alloy supplier" in and got Mallory.
http://www.mallory.com /
Mallory 1000 looks like the stuff. Not too hard so it should machine fine.
http://www.mallory.com/english/engmats.htm
--
Dave Baker



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BTW, it might be cheaper to buy tungsten darts and machine them down. Something like these.
http://www.a180.co.uk/shop/section.php?xSec=9
--
Dave Baker



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wrote:

what do you mean... wow what a coincidence ..the guy asked about it three years ago !!!
you're just using his post to sell your wears .
all the best.markj
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wrote:

Not only that, but I'd replied within 5 1/2 hours of the original post pointing the OP to a chap selling some 1" dia x 8" long scrap Elkonite on Ebay that 'd thought about getting.
I got that piece with the only bid at 5.99. Scrap Elkonite is worth very little, no matter that It costs new.
regards Mark Rand RTFM
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