I’m way late to the party here, since the US Postal Service’s “If it fits, it ships” slogan has been around for a good four years now. The humor potential is also seriously dampened by sneaky weight limits that are advertised with much less vigor than the slogan. Still, let’s look at how to get the most bang for your buck in terms of hernia inducing packages.
Dylanstiles.com recommended osmium in a 2010 post. But since it would take around $5 million to fill the “Large” flat-rate mail box with osmium, he recommended depleted uranium as a second choice. Unfortunately, I don’t think Walmart carries depleted uranium.
A year after that post, somebody actually did this, but with pennies. Copper is actually a great choice, since it is at the peak of a density plateau among the lighter transition metals and is also reasonably cheap. Unfortunately, most US pennies are zinc now, which is a lighter metal. They could only manage to get a bit less than 60 pounds of pennies into the box, well shy of the 70 pound limit.
If you want to get the maximum mass into a USPS box without spending millions of dollars, I’m thinking tungsten is the way to go. With a density of 19.25 g/cc, it is damn near as dense as osmium. But more importantly, you can buy tungsten … from Amazon.com … in the fucking TOY section! And that ain’t even the best part. The best part is that it sells in quarter inch cubes, meaning you can fill that USPS box completely, without leaving even a fraction of an inch of space unused.
Why the toy section? Tungsten cubes are used as weights for Pinewood Derby cars. 🙂
The “large” flat-rate box measures 12″ x 12″ x 5-1/2″, or 792 cubic inches. That will fit 50,688 of the quarter-inch tungsten cubes sold by Amazon, each weighing 0.17 ounces. That works out to around 551 pounds (250 Kg). This will cost between $42,000 and $50,000 retail, depending on your source. The $11,000 price in the table below is bulk.
|Element||d (g/cc)||US Pounds||Estimate Cost|
So, if you decide you want to be a total dick and try to send somebody some metal in a USPS flat-rate box, tungsten is definitely the way to go. It’ll cost over $10K to fill the larger flat-rate box, but your package will be over 550 pounds — enough to get you sent off for a mental evaluation, at minimum. 😛