Re: Weighing Freight Car Models with Liquid Gravity
There is a commercially available Tungsten alloy shot, formed to have similar density as lead... without the lead.... for lead free states.
Hevi-Shot Tungsten Alloy Shot 3 lb
Pure W isn't all that hard. Even with the harder alloys, there are specialist shops that work with it 90WNiFe alloy and can mill and cut that fine.
In fact, for extremely small dia wire, W is often the cheapest you can get per meter, as it pulls very fine without breaking. (For $170, you can get 0.0005" electropolished wire in 500m spools)