You wanted to, I did..Buyer Beware...Wash edge

Discussion in 'Error Coins' started by mattman, Mar 17, 2007.

  1. Delmer

    Delmer New Member

    you're gonna laugh.. but I brought my GRAINES scale and calipers and picked 2 up directly from the seller. 123.4 graines... matched exactly 3 other lettered versions I brought.

    a mechanical graines scale can be had at any gun shop with reloading equipment. 45 bucks.. and less on the net.

    no way someone is gonna get enough material off to fool the graines scale. If you want to mail me one I'll weigh it.. if you make one above 117 graines I'll be extremely suprised. you'd have to start with a shallow strike and a heavy coin.. I've seen 125.6 grain ones.
     
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  3. mattman

    mattman New Member

    SURPRISE! Here's the only one I made and I re-weighed it using grains and it's 121.0
     

    Attached Files:

  4. Delmer

    Delmer New Member

    EXTREME suprise! wish I could see the rim up very close for grind marks.. I'll raise my expectations to what I read rather than what I THOUGHT... which is "120.3 gaines is suspect". (yours still wins there though!)

    The text I read also said that 125 graines was proper, plus or minus 4.63 graines (I translated the grams listed in the original text)

    I've got a 4.4 grain nugget of natural austraillian gold and although it's volume is smaller than what would have to be removed from a GW for it to be 'out of spec', to the eyeball it still looks like a pretty big chunk.

    Myself, I now wouldn't go NEAR anything below 123.. just because when the people become more aware of the fakes.. my REAL one will turn SUSPECT!

    DIAMETER is definetly a good doublecheck when buying.

    Thanks for doing that mattman! It needed to be done. If you care to, do another one and get the PRE-GRIND WEIGHT!!! (and diameter)
     
  5. mattman

    mattman New Member

    the first post shows the coin before and after with weights and measures, I'm sure there is a way to convert grams to grains but I don't know it. Measuring in mm I assume would be more accurate.

    Mattman
     
  6. Delmer

    Delmer New Member

    aah ok sorry.. I missed it. duuh..

    Your BEFORE weight..
    7.97 grams = 123.00~ grains

    Your AFTER weight..
    7.86 grams = 121.30~ grains

    gatzdon's post - official weights converted:

    8.1g +/- 0.3g or 125.00 grains +/- 4.63 grains. Thats 120.37 to 129.63 grains is normal.

    I have yet to see one over 126.7 grains though, or under 121.4 grains. a general average of the ones I've weighed (20 or so just now) is 123.6. all mine are from philly.





    So you actually started with a coin that was slightly UNDER average and STILL ended up over the "suspect" weight. boy..
     
  7. gatzdon

    gatzdon Numismatist

    It doesn't matter if OP's coin has grind marks as his is more of a proof of concept and not meant to be a true fake. Grind marks are a matter of attention to detail.

    OP basically has proven to us that you cannot got by weight to ensure you are not buying a coin where the edge inscription has worn off. I say worn off because in addtion to avoiding frauds, we need to also be careful we are not mistaking coins where the edge normally wore off for an error.

    The only true method to discriminate is by measuring the diameter.
     
  8. Delmer

    Delmer New Member

    Great stuff huh!

    Just like filing off serial numbers on a firearm.. if buffed smooth, the fact that a number existed is visible because of the dinged metal that penetrated well below the deepest trough of the incused letter.. Scuffs will disguise the warped metal.

    taking off the buffing marks to further disguise the fake will reduce the weight,, but I was mainly interested to see what the markings looked like, so I might be able to spot a cheezy fake at least. Buffing might round the edges more too.

    He mentioned that he could smack the coin with a board and gain diameter so THICKNESS would also need to be checked. When I get home I'll check a few.. down to 0.001" and post.

    I know.. If you can put it through a coke machine it's real (kidding)..
     
  9. USS656

    USS656 Here to Learn Supporter

    Measured 10 brand new just out of a roll with a digital caliper

    All measured 26.50mm across
    Each thickness varied based on location around the rim
    Highs were 2.07mm
    Lows were 1.98mm

    Some were consistently around 2.05mm or 2.01mm but most varied depending on position by as much as .08mm.
     
  10. Delmer

    Delmer New Member

    Measured 6, new roll P mint (handled slightly.. error checked 6 times ;P) with mechanical dial calipers

    078 080 080 080 0805(best estimation.. needle in the middle) 081

    0.080" (2.032 mm) is the median.
    0.078" (1.981 mm) was the low, in one extreme case (hence I didn't want to list the average)
    0.081" (2.057 mm) was the high.

    I did 7 more real quick, and they all were nailing .080 to .0805

    This all may be moot to someone who brings a scale and calipers to test one.. because he (she) can also bring a roll of coins with them as control subjects ;)

    still fun to do.. Good luck to all.
     
  11. Conder101

    Conder101 Numismatist

    If you are going to measure the diameter do it in mm NOT inches. Especially if your caliper only goes to two decimal places. The difference shown in the first post was .01 inches which doesn't sound like much. Until you compare it to mm and against the tolerances. .01 inches is .25 (rounded to two places) mm and the tolerance in the diameter is .003 inches or .08 mm. The original size he showed of 1.04 inches is 26.49 mm. Spec is 26.5 a difference of .01 mm. the .01 inch decrease in diameter is as I said .25 mm or a little more than THREE TIMES the legal mint tolerance. That is a BIG discrepancy.

    Also examine the edge under a loupe. A genuine smoothie will have a multitude of vertical lines of differing lengths on the edge. These are remnants of the shear edge from the blanking, and ejection scratches from being forced out of the collar after striking. The areas that don't show the lines will show the flat smooth appearance of metal forced against the flat collar. Both of these are removed in a grinding, buffing or milling procedure. Typically those processes willl leave tool marks that run horizontally around the coin and not vertically across the coin. another feature is the shape of the edge itself. On a genuine smoothie there is a flat on the edge and then bevels top and bottom from the flat to the rims. The flat is cuase by the expantion of the coin against the collar, but the pressure usually isn't enough to form the edge completely so you get the bevels. When the coin is compresses in the lettering die it also squares up the edge some more. Also if someone sands off the lettering the edge will usually be rounded and not show the flat area. If it is milled it will usually be very squared off and not show the bevels unless the machinest knows enough to put them back on.

    A real good way to learn what the edge of a genuine smnoothie would look like is to closely examine the edge of a new Sac dollar. Look at the shape, the surfaces and the characteristic scratches. Once you know what a genuine edge looks like you should not be fooled by a home made fake.
     
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