I am looking for tolerance info. for Morgan Dollars. Weight the target is well known 26.73 grams with tolerance of +/- 0.097g. However, I have not found tolerance info for diameter (38.10 mm) or thickness (2.40 mm). In my collection I have 6 that weigh more than 26.73 but less than 26.827 so by weight they are within tolerance. Diameters for the 6 in question is 38.10 mm but thickness varies in the group upto 2.47 mm. Anyone have info regarding the thickness tolerance? thanks
The thickness of the strip used for punching planchets were determined by using rollers to slowly approach the thickness needed ( using a dial indicator) so as after several annealing passes, and using a standard punch would produce a planchet within the tolerance of a morgan weight. The collar would allow little change in diameter, and if the planchett was the correct weight ( within tolerances), the height of the coin would also have minimal variation. Only the weight had the tolerance dictated by law. If the die distances were slightly inaccurate, the die features might cause a slight variation in height, but since they were set and reset after die change, there would be difficulty determining tolerances by law. After all, the purpose then was the value of the weight of silver and not variations ( errors) so prevalent today.
What do you guys buy to measure coins -- can someone recommend a digital weigh scanner on Amazon or somewhere ? If the MSD is in a slab, then I presume you just add the weight of the slab to the MSD ?
I suspect the PCGS laser scanner device could be used for such, with a little creative reprogramming of course. I have a surplus lab Mettler H30. Cost about $60 a decade ago as colleges going to digital Chinese stuff. Weighs up to 160grams, resolution 0.1mg ( .0001g ). If you buy inexpensive electronic digital balances, most are made and rebranded from only about a few manufacturers. Amazon has a large selection. Since they all round off electronically, be sure to get one with a calibration function, calibration weight, tare function , and one more decimal place than you think you will ever need. Usually a .001g will do , the fourth zero is a large jump. If you are going to measure bullion bars, etc. take that into consideration also. Generally 50-60 grams will do most coins.
DG, right now I only see myself buying bullion coins, Saints, and Morgans....no rush, but if you have a good name or link to one on Amazon I would appreciate it.
Dave, the old theory that many of the so-called "weak strikes" that came from the New Orleans Mint were actually cases of improper annealing of the planchets. If I recall correctly, Roger Burdette mentioned this in his book, From Mine to Mint. Chris
Have not been collecting that long but it appears that only about 6% of the Morgans have been on the "heavy side." Examples I've seen are in common years 1886, 1890 S, 1891 S, 1896, and 1897 so there would not appear to be much value in attempting to fake these? The obvious fakes I've seen have been "light" and thick or wrong diameter. Would you consider a 1886 Morgan that weighs 26.81g (+/- 0.01g) to be fake if the diameter is correct? With 19 M+ minted, does note apprear to be a high value target year for counterfitting?
