Gold & Silver Forum - Silver content in US coins?

Quote:

Weight/purity of silver in US Silver Coinage
Silver Dollars
Half Dollars
Quarters
Dimes
Eisenhower Dollar
Minted 1971-1978
0.3161 Troy oz. fine silver

Only some 1971-1976 are silver!
Kennedy Half Dollar
Minted 1964 to present
0.36169 Troy oz. fine silver (1964)
0.14792 Troy oz. fine silver (1965-1970)

Only 1964-1970 are silver, and only 1964 are 90% silver!
Washington Quarter
Minted 1932-present
0.18084 Troy oz. fine silver

Only those minted from 1932-1964 are silver!
Roosevelt Dime
Minted 1946 to present
0.07234 Troy oz. fine silver

Only those minted from 1946-1964 are silver!
Peace Silver Dollar
Minted 1921-1935
0.77344 Troy oz. fine silver
Franklin Half Dollar
Minted 1948-1963
0.36169 Troy oz. fine silver
Standing Liberty Quarter
Minted 1916-1930
0.18084 Troy oz. fine silver
Mercury Dime
Minted 1916-1945
0.07234 Troy oz. fine silver
Morgan Silver Dollar
Minted 1878-1921
0.77344 Troy oz. fine silver
Walking Liberty Half Dollar
Minted 1916-1947
0.36169 Troy oz. fine silver
Barber Quarter
Minted 1892-1916
0.18084 Troy oz. fine silver
Barber Dime
Minted 1892-1916
0.0723 Troy oz. fine silver

Barber Half Dollar
Minted 1892-1915
0.36169 Troy oz. fine silver

NOTES:
"Fine Silver" is 0.999% pure. When you take the alloying of the coinage into account, US silver coinage 1964 and earlier is 90% fine silver by weight. 1965 and later is 40% fine silver by weight.
This table covers all US silver coinage, regardless of percent silver content, that the junk silver buyer is likely to encounter. Remember that 1964 and earlier is 90% fine silver, while 1965 and later is 40% fine silver. Remember to base your calculations on the coin and the percentage of silver content based on the date of mint. You have been warned!

I would suggest avoiding 1965 or later coins to simplify your life. By doing this, you can boil the above down to this:
Silver dollars contain 0.77344 Troy oz. silver content
Half dollars contain 0.36169 Troy oz silver content
Quarters contain 0.18084 Troy oz silver content
Dimes contain 0.0723 Troy oz silver content
http://web.northstate.net/~seward/Su...unk_silver.htm

I have a question regarding post 1965 coins? At what date did they stop being 40% silver? The above author seems to imply that they were 40% silver after 1965.

Also does any one have any other resources that simply list the dates and silver content of US coins?

Thanks for any help.