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.
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.
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.
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).
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
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.
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