Densest Building Materials

[Richard Wallace]

Originally Posted by Andy Baker

You may as well just pull out the big guns and use a stack of these!

Uh, Andy ... those little beauties cost $240 each and are smaller than a penny. Each one contains about 1.2 gram of gold, alloyed with a smaller mass (but about equal volume) of something with lower density -- maybe silver, maybe copper or ? Mass of each coin is not specified in the ad, but is probably about 2 gram; i.e., about 80% the mass of a penny.

In cost-effectiveness terms, that's a lot of buck for not much bang.

A more practical alternative, and one that many FTC teams would actually choose, is steel ballast. One example is 0.75" diameter low carbon steel bar stock, McMaster 8920K19, $31.12 for a 6 ft. bar. An eight inch length of this bar stock would give you the same ballast mass as the aforementioned eleven inch stack of pennies, at a pro-rated cost (which assumes you have another use for the rest of the bar) of $3.45. About 1.9 times the cost of the Penny ballast, with 11/8 = 1.375 times the density. Steel is looking good compared to U.S. Nickels, and VERY good compared to gold coins.

But again, in terms of cost-effectiveness, the U.S. Penny is hard to match.