Except for the famous "war nickels" made from mid-1942 to 1945, the answer is "none", because all other US nickels don't contain silver. Since 1866, the coin has been made of an alloy of 75% copper and 25% nickel.
If you have war nickels with a large mint mark on the back, these do contain a small amount of silver - 1.75 gm to be exact. Because one troy ounce is about 31.1 gm, you'd need 31.1 / 1.75, or about 18 war nickels to contain a troy ounce of silver.
One silver war nickel weighs 5 grams and contains 35% silver, or 1.75 grams of silver per nickel. One troy ounce is 31.1 grams. It would take 18 war nickels to make one ounce of silver.
5
14oz
Silver half dollars have about 0.362 Troy oz. of silver in them, so 3 of them would be 1.086 Troy oz.
100 silver U.S. dimes make up 7.23 troy ounces of silver.
War nickels contain about 1.5 gm of silver so they're worth about 1/20 of the current price of 1 oz of silver for the metal alone. A high-grade one can be worth up to $300 depending on condition.
5 US ounces is equivalent to 142 gm. A US nickel weighs 5 gm so there are 142/5, or approximately 28, nickels in 5 ounces. A Canadian nickel weighs 3.95 gm; 142/3.95 is roughly 36 coins.
7.15 oz.
it takes nearly 3 - 90% silver half dollars to make an oz of silver IF IF IF the coins are not worn down.. the least worn are the franklin and Kennedy halves the most worn are the walking liberties halves.. it can take up to 6 of them[WL's] if they are really.really worn to make an oz of silver! be careful as Midas Resources,Ted Anderson,and Alex jones claim 2 half dollars equal 1 oz of silver, which is not correct.
Four 40% Eisenhower dollars= a little more than 1 & 1/4 oz of silver.
14 silver dimes equal just a little more than 1 troy oz. Each coin has .07234 oz of pure silver.
1,500 grains is 3.42857 oz. Sterling silver is only 92.5% pure silver, so the actual silver content of 1,500 grains of sterling silver is 3.17143 oz (at about $18.50/oz = $58).