You don't have to add cts (Comment to short), on the forum...
mf thats not meltable
mf those are pretty horrible for heat conductive (except brck somehow)
might as well link this: https://powdertoy.co.uk/Wiki/W/Element_conductivities.html
tungsten
https://powdertoy.co.uk/Wiki/W/Element_conductivities.html
choose the one you like
Those are heat conduction speeds..
"This is a table of heat conducting speeds for all the elements of Powder Toy." - says towards the top of the page.