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
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
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.
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
In article , Andrew Mawson
writes
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
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
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
High
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
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
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