1964-P Washington Quarters weight variance

[Apolylogy]

dHi everyone,

i am new to collecting but I was under the impression that these quarters weighed 6.25 grams.  I have one that weighs 6.1 and another that weighs 6.4 grams.  Both were weighed by the same digital scale and the scale registers others 1964's at 6.25

what could cause these drastic variances?  Thanks for any help!

[WoodenJefferson]

6.25 is the 'standard' weight the 90% silver quarter is supposed to weigh but there are variances as you have noted. The 6.40 is on the allowable high side but 6.10 is too low. The silver/copper metal was rolled out to a specific thickness and when the planchets were punched out, they would be the correct weight. I have read where the beginning and the end of the strip was rolled out too thin which resulted in a small fraction of planchets that would be a few 10ths of a gram short. When your making millions of coins on a mass scale, these few under weight planchets went to the presses anyway amd now you found them.

For 1948 to 1964 the weight is 6.25 grams with a tolerance of +/- .194 grams.

Best answer I can come up with, there maybe other reasons as a chat board is a collective opinion.