How Many Silver Half Dollars Make a Troy Ounce?

The silver content of half dollars varies significantly by mintage year and series. Understanding these differences is essential for accurately determining the intrinsic value of these coins. This article clarifies specific silver compositions and explains how to calculate the number of half dollars needed for a troy ounce of silver.

Understanding Silver Content in Half Dollars

The United States has produced half dollars with varying silver compositions. Before 1965, half dollars, including types like the Walking Liberty, Franklin, and 1964 Kennedy, were 90% silver and 10% copper. These 90% silver half dollars weigh 12.50 grams each.

In 1965, due to rising silver prices and demand, coinage law changed. From 1965 to 1970, Kennedy half dollars were produced with a reduced silver content of 40%. These 40% silver half dollars weigh 11.50 grams each. After 1970, half dollars issued for general circulation typically contained no silver, instead being made from a copper-nickel clad composition.

The Concept of a Troy Ounce

A troy ounce is the standard global unit for weighing valuable metals such as silver, gold, and platinum. This specialized unit ensures consistency in the trading and valuation of these commodities. One troy ounce is equivalent to approximately 31.1035 grams.

It is important to distinguish a troy ounce from the more common avoirdupois ounce. The avoirdupois ounce, which weighs approximately 28.3495 grams, is used for measuring most everyday goods. The troy ounce is specifically designated for precious metals.

Calculating the Number of Half Dollars for a Troy Ounce

Determining how many silver half dollars are needed for one troy ounce of pure silver involves a calculation. The process requires knowing the gross weight of the coin and its silver fineness, which is the percentage of pure silver it contains.

First, calculate the pure silver content within a single coin by multiplying its gross weight by its silver fineness. Once the pure silver content per coin is established, the next step is to divide the weight of one troy ounce by this calculated pure silver content. This yields the number of half dollars required to reach the one-troy-ounce threshold. This methodology provides a precise way to assess the silver value held within a collection of half dollars.

Specific Examples for Common Silver Half Dollars

Applying the calculation method reveals the specific number of common silver half dollars needed for a troy ounce. For pre-1965 half dollars, which contain 90% silver and weigh 12.50 grams, the pure silver content per coin is 11.25 grams (12.50 grams 0.90). To obtain one troy ounce of pure silver (31.1035 grams), approximately 2.76 half dollars are required (31.1035 grams / 11.25 grams per coin). Therefore, three 90% silver half dollars will generally yield more than one troy ounce of pure silver.

For the 1965-1970 Kennedy half dollars, with their 40% silver composition and gross weight of 11.50 grams, the pure silver content per coin is 4.6 grams (11.50 grams 0.40). To accumulate one troy ounce of pure silver, approximately 6.76 of these coins are necessary (31.1035 grams / 4.6 grams per coin). Consequently, seven 40% silver half dollars would be needed to exceed the one-troy-ounce mark.