Do US silver coins ever weigh over their standard?

[aaa30040]

I just got a digital scale today and have been weighing my very small collection. Of the 20 half dollars I have, 19 weigh 12.5 grams or slightly less for worn examples. But one weight is 12.6 grams. It is a Franklin that looks new.

Does that mean it is fake?

[barrytrot]

It's either fake or a mint error (wrong planchet or thick planchet).

If it's a mint error it is a really good one, so definitely try to get it authenticated.

[SoFa]

I think 0.1g is within the tolerance. But I can't find the official specs.

[Country]

When New:

90% Halves - 12.50 grams
40% Halves - 11.50 grams
Clad Halves - 11.34 grams

There are slight variations of tolerance due to minor differences in blanks.

Of course, for accurate weighing, you need a scale that measures in hundredths of a gram.

[Robarons]

Yup in 1963 and earlier when these coins were made I can see some variations in 90%

But nothing too extreme, unless its a error

[Oakair]

When New:

90% Halves - 12.50 grams
40% Halves - 11.50 grams
Clad Halves - 11.34 grams

There are slight variations of tolerance due to minor differences in blanks.

Of course, for accurate weighing, you need a scale that measures in hundredths of a gram.

pshh...hundredths are for the common man, if you want accuracy, MG scales are the way to go...if it cant cut it in a lab, i wont use it

i do actually have a mg scale, but its sooooo annoying to be able to see every milligram your missing haha

[Engineer]

I tried sorting a bag of mercs by weight to see if the weights would approximate grading quality. It didn't work.

In some cases, XF dimes weighed the same as the G4s.

[68Camaro]

I tried sorting a bag of mercs by weight to see if the weights would approximate grading quality. It didn't work.

In some cases, XF dimes weighed the same as the G4s.

The closer you get to clean the more scatter there is. In the more worn coins there is a correlation. I'm surprised you couldn't see it between XF and G4. When I did an evaluation of hundreds of mercs last year I found a solid correlation between several major coin features (edge lip, merc reed clarity, etc) and weight. But that said, it's a statistical correlation not a hard and fast law, and I wouldn't bet my house on it for every individual instance. I've seen BU coins that were both light and heavy, and it did seem to vary by coin type and year. Probably a function of the accuracy of the input stock, as mentioned above.

[cecropia_moth]

I've found non worn 40% halves that weigh anywhere from 11.1 - 11.8 grams. They are supposed to come in at 11.5 grams. I'm positive none of the ones I've handled are fakes, just variance in planchet weight.

Jeff

[silver]

I have 20 uncirculated 1964 Kennedy halves that vary from 12.2 to 12.6. Is that normal?
ED

[68Camaro]

I've seen some small variation, but 12.2 is out of bounds and would send up a flag to me. You really need a scale reading to the hundredths to be sure about the 12.6. 12.55 would read 12.6. I'll grab a handful tonight and show the typical scatter.

When weighing rolls of JFKs most are 249.5-250.5. I only rarely see rolls below 249 - some, but not many. Don't think I've ever seen a roll below 248 (sure it could happen). At 249 they would be averaging 12.45.

I've got a roll in my desk that is 248.5-ish, and I'll pull it out and see what they are individually. But that'll be tonight.

[silver]

Have there been reports of counterfeit halves? I bought this roll of BU '64 Kennedy halves on eBay. I also bought a roll of '63D BU Franklin halves from the same seller and the weights are not quite right either. I use two different calculators to weigh them and even if the calculators are not right the disparity among the coins still indicate something is wrong. I'd hate to think they are counterfeit.
ED

[brian0918]

Have there been reports of counterfeit halves? I bought this roll of BU '64 Kennedy halves on eBay. I also bought a roll of '63D BU Franklin halves from the same seller and the weights are not quite right either. I use two different calculators to weigh them and even if the calculators are not right the disparity among the coins still indicate something is wrong. I'd hate to think they are counterfeit.
ED

Was the seller a reputable coin dealer? Can you give us the link to their ebay store?

Also what are the scales you used, what is their precision rating? You should get one that is precise to .01 grams.

[silver]

How do I go about linking to the seller? I'm pretty dumb about those type of things. The seller has over 17,000 feedbacks and only one negative in the last year. I know times are tough so I wouldn't put anything beyond desperate sellers. His user name is djf-coins if that would help.
ED

edit: The calculators I use are not of the expensive sort that would be more reliable. Like I said the disparity among the coins is still too great.
ED

[brian0918]

My scale was under $10 and is accurate to 0.01 grams.

Here's one
Here's another

[silver]

Brian,
I just this moment bought the 300g-0.01g calculator from eBay.
Thank you
ED

[68Camaro]

If your scale is repeatable, but only weighs to .1 g, here's a technique to at least see what you've got.

Divide all of like type (don't mix the Bens and JFKs) into groups of four coins (50 g nominal). Weigh all the groups, write down the numbers keeping them straight, and sort them in piles by weight from highest to lowest. (Post those numbers, if you want some comment.)

Take the 4 sets of lowest weight coins, divide each in two into groups of 2 coins, weigh them (25 g nominal), writing down the numbers and keeping them straight, and sort the pairs by weight. Combine the two lowest weight sets (4 coins), weigh them, and report the weight. If that lowest weight set of 4 weighs less than 49.5 g something is shockingly wrong. Either with your scales, or the coins themselves. Report each of the individual weights if you want further comment.

[brian0918]

I've only got a handful of 90% halves, but I have a lot of 40%, mostly from circulation, so I'll test mine out to see the variance.

[slickeast]

A lot of Franklins I have weighed were over 12.5. Kennedys were dead on. WL were all over the place due to wear but never over. I think Ray bought the Franklins. If he still has some maybe he could weigh 40 to see if they are over 500grams

[brian0918]

I bought a full Franklin half dollar set, but don't want to take them all out of the book to weigh them.

[68Camaro]

Franklins vary some by year in the 50s, for a given condition. I don't recall which years, but there were some years that were consistantly off-nominal. But slightly, nothing like we're talking about above.

[beauanderos]

A lot of Franklins I have weighed were over 12.5. Kennedys were dead on. WL were all over the place due to wear but never over. I think Ray bought the Franklins. If he still has some maybe he could weigh 40 to see if they are over 500grams

dude... those were flipped within a week. I can't keep halves in stock, everyone wants them.

[brian0918]

I weighed the half dozen 1964's I have, and the range was from 12.32 to 12.55. The lowest one doesn't look like it has much wear on it, except for a lot of crud and stains. It sounds just like the others, so I don't think it's a fake.

I also weighed my 30+ 40% halves, and the range was 11.21 to 11.78. The lower-end ones do show some wear, but not significant amounts of it. So I think they're mostly underweight just due to minting differences.

Interestingly, the heaviest 40% silver half I found was a Proof 1976-S, which came in at 11.8 grams.

[68Camaro]

Popuation of 20 standard low-circulation 64s

On a 0.1g scale they weight 250.0 On a 0.01 g scale they total (from individual weighings) 250.08

The population and stats:

12.48
12.30
12.43
12.54
12.57
12.66
12.57
12.56
12.52
12.46
12.68
12.38
12.55
12.61
12.56
12.52
12.42
12.32
12.39
12.56
250.08 Total
12.504 Average
0.104498804 Std Dev
0.00835723 CV
0.835722999 CV %
12.3 min
12.68 max

The range of individuals is a bit surprising. It does seem to be fairly normally distributed, and in this small population (which would be expected to see about 2-sigmas actually within the population) the min and max were just over 2 sigmas off the mean. So 12.5 +/- .2 is observed, though the average of 20 is essentially exactly 250.

I had 7 proofs handy, and they came in at

12.48
12.49
12.40
12.67
12.61
12.36
12.39

I don't see any difference in the proofs.

[silver]

68camaro,
This is what I came up with for weights. I first weighed the whole roll. I came up with 248.5 and dividing by 20 Igot 12.45g per coin.
I then divided the roll into five fours and weighed them. I got 50.3_49.7_ 49.7_49.7_49.2. I took the two lowest and divided into eight twos. I got 25.2_25.1_25.0_25.0_ 24.9_24.9_24.8_24.5. I took the two lowest, combined and weighed. I got 49.2. I guess I did it right.

Thank you for your patience.
ED
edit for content.