Comparison of two siver bullion coins.Please explain.

smprfi

American silver eagle is 1 troy ounce with a diameter of 40.6 mm and thickness of 2.98 mm. Purity is .999 fine
Australian Dragon Silver Coins is 1 troy ounce with a diameter of 40.6 mm and thickness of 4.00 mm. Purity is .999 fine

My question is if the two coins are of the same weight diameter and purity: How can the thickness be different?

Darkhorse

Australia must be using crazy metric troy ounces or something.

supercoin

A troy ounce is always a troy ounce.

Maybe the Aussie coins are just higher-relief designs... i.e. deeper valleys and higher mountains, but same amount of silver.

itsnotjustme

Where is the thickness measured? Since a coin is not of constant thickness, if one measured the max, and the other the min, that may account for it.

cosmicdebris

We are only talking .039 of an inch.

smprfi

ttt