Peace dollars and their various weights, sizes? Mint spec?

[Zap]

The peace dollar is my favorite coin by a mile. I recently purchased 20 online and went to work with my scale and digital calipers. Here's what I found:
Out of 20 coins the lowest weight was 26.5g and the highest was 26.7
The diameters ranged between 38.02 and 38.12
The thickness ranged between 2.46 and 2.75mm with most falling somewhere between 2.55 and 2.67. Visibly one can easily distinguish the thinner ones from the fatter ones.

My question is this: If these all rolled out of the mint @ 2.4 or 2.47mm thickness, how over time did they gain in this measurement?

Thank you.

[omahaorange]

Keep in mind that coin planchets are close, but not exact. The Mint works within tolerances, like any machine shop. For the Peace dollar, the planchet specification was 26.73 grams. The tolerances also hold for the diameter and thickness. The Law allows a +/- tolerance, but at the moment I can't recall the percentage. Wear can account for some loss of weight and thickness. If in doubt, take them to a local dealer for verification.

[Zap]

I don't trust that my local dealer has more information than I do. They all ping, none are magnetic, and when buying raw coins that you can't clean luster can be a judgement call. The tolerances should be made available as a guide by the us mint to discourage counterfeits.

[omahaorange]

The last poster in this thread (as of now) seems to have it right.

http://www.cointalk.com/t100671/

After reading that thread I think I understand your question a little better.

Keep in mind during the pressing the metal of the planchet is forced into the incuse designs in the die, so there will not be a consistent thickness throughout the surface of the coin. I'm not sure where you would measure the thickness of the coin, but the fields would probably give you the most accurate indication of the thickness, not the rim or the portrait.

The tolerances are out there, mostly buried in the various acts regulating coin production. Any edition of Coin World's "Coin Almanac" will give specifications and tolerances for all but the thickness of the Peace Dollars (an other coins). My guess is this information is not readily available so as to thwart counterfeiting. Much in the same way the exact composition of the paper used for bills is not readily available.

[SuperCoins]

Hrmh...I don't see how you can have a 'favourite coin' like that...I see more of a point in having a favourite type of coin, like Celts, or Romaion coins...I love the 19th-Century 'unofficial farthing' tokens myself, as you get such variety and history combined in one..