What does .1479 ASW mean?

Drake writes: I have a Half Dollar – Kennedy 1965-1969 (40% silver) .1479 ASW. How much money is it worth and what does .1479 ASW mean?

.1479 ASW means the Actual Silver Weight is .1479 of a troy ounce. Precious metals are measured in troy ounces. There are 12 troy ounces of 31.1033 grams/ounce in a troy pound. If you multiply the decimal .1479 by the world price of silver, you will realize the intrinsic metal value of the coin. For current silver prices in troy ounces, see the CoinSite Precious Metals page.