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
Andrew Mawson - 18 Jul 2007 07:56 GMT
> 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
[quoted text clipped - 4 lines]
>
> Thanks
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
David Littlewood - 18 Jul 2007 12:14 GMT
>> I'm just planning my next project which calls for the use of High
>Density
[quoted text clipped - 11 lines]
>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
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

Signature
David Littlewood
Malcolm Stewart - 18 Jul 2007 08:15 GMT
> 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
My tungsten carbide gauge blocks have an SG of around 17, I believe. They
certainly look like metal, and they conduct electricity.

Signature
M Stewart
Milton Keynes, UK
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Tom - 18 Jul 2007 08:20 GMT
> 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
[quoted text clipped - 5 lines]
>
> Thanks
Mallory metal?
Tom

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Peter Fairbrother - 18 Jul 2007 08:21 GMT
> 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
[quoted text clipped - 5 lines]
>
> Thanks
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
Dave Baker - 18 Jul 2007 08:28 GMT
> 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.
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.

Signature
Dave Baker - Puma Race Engines
Prepair Ltd - 18 Jul 2007 10:11 GMT
>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
[quoted text clipped - 4 lines]
>
>Thanks
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
prepair@easynet.co.uk
http://www.prepair.co.uk
Steve W - 18 Jul 2007 17:06 GMT
> On Wed, 18 Jul 2007 07:19:00 +0100, "Steve W"
> <steve.withnell@btinternet.com>
[quoted text clipped - 21 lines]
> prepair@easynet.co.uk
> http://www.prepair.co.uk
Looks like the economic option to me, the SG is about 14.5 from google so
pretty close.
Mark Rand - 18 Jul 2007 12:57 GMT
>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
[quoted text clipped - 4 lines]
>
>Thanks
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160136230194
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
mikemcd - 19 Jul 2007 11:37 GMT
> >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
[quoted text clipped - 13 lines]
> Mark Rand
> RTFM
I think theres a material with a trade name like densamet
Trevor Jones - 18 Jul 2007 14:02 GMT
> 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
[quoted text clipped - 5 lines]
>
> Thanks
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
Nick Mueller - 18 Jul 2007 15:17 GMT
> Anyone know of a current supplier, Google isn't my friend on this one.
You should google with "densimet"
Nick
rocketmentor - 18 Feb 2010 02:13 GMT
Steve W Wrote:
> I'm just planning my next project which calls for the use of Hig
> Density
[quoted text clipped - 6 lines]
>
> Thanks
Wow what a coincidence, I just found a billet of Elkonite with
measured density of 16.986! It's 1.989" OD by 1.165" long/thick. It cos
about $350-400It's machinable too. Machines like cast iron. I believ
it's 90% tungsten the balance copper and nickel. I'm going to list it o
ebay unless you want to buy it. It is very expensive though for just
counter weight. Your choice.
Thank you,
Ke
--
rocketmento
Dave Baker - 18 Feb 2010 11:06 GMT
> Steve W Wrote:
>> I'm just planning my next project which calls for the use of High
[quoted text clipped - 16 lines]
> Thank you,
> Ken
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

Signature
Dave Baker
Dave Baker - 18 Feb 2010 11:21 GMT
> Google didn't seem to have any problem for me at least. Just stuck
> "tungsten alloy supplier" in and got Mallory.
[quoted text clipped - 4 lines]
>
> http://www.mallory.com/english/engmats.htm
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

Signature
Dave Baker
mark - 18 Feb 2010 12:06 GMT
On 18 Feb, 02:13, rocketmentor <rocketmentor.46k...@rcgroups.com>
wrote:
> Steve W Wrote:
>
[quoted text clipped - 23 lines]
> rocketmentor's Profile:http://www.rcgroups.com/forums/member.php?u=302466
> View this thread:http://www.rcgroups.com/forums/showthread.php?t=714981
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
Mark Rand - 18 Feb 2010 20:28 GMT
>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
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