Sort through a coffee can of old half dollars and you may be holding three different coins wearing the same face. The 1964 Kennedy is 90 percent silver. Anything dated 1971 or later is copper and nickel with no silver in it at all. Between those two sits a six year run that gets overlooked at kitchen tables and misjudged at coin shows, and it is the one worth learning before you buy a pile or sell one.
What 40% silver half dollars actually are
From 1965 through 1970 the Kennedy half dollar was struck as a silver clad coin with a net silver content of 40 percent. The construction is a sandwich: outer layers of 80 percent silver and 20 percent copper bonded to an inner core of roughly 20.9 percent silver and 79.1 percent copper. Average the whole thing and you land at 40 percent silver, 60 percent copper.
Each coin weighs 11.50 grams, a little lighter than the 12.50 gram 1964 issue and a little heavier than the 11.34 gram copper nickel halves that came after. The diameter never budged at 30.61 mm, which is why all three eras still stack in the same tube. Actual silver weight works out to 0.1479 troy ounces per coin.
That number is the whole story in one figure. A 1964 half carries 0.3617 troy ounces, so a silver clad half holds about 41 percent as much metal as the coin it replaced. At the bag level, $1,000 face value in 40% halves comes to roughly 295.8 troy ounces of silver. The same face value in circulated pre-1965 dimes, quarters and halves runs closer to 715 ounces. If you are used to doing the math on 90 percent junk silver, the divisor is different and the mistake is expensive in both directions.
The law that created them
President Lyndon Johnson signed the Coinage Act of 1965 on July 23 of that year. The problem it answered was simple arithmetic. Silver had climbed far enough that the metal in a dime, a quarter or a half was worth more than the coin’s face value, so the coins stopped coming back. Banks ran short. The Act pulled silver out of the dime and quarter entirely, replacing it with copper nickel bonded to a pure copper core, and cut the half dollar to 40 percent.
Why spare the half at all? CoinWeek describes the 40 percent figure as a compromise, enough silver to satisfy the silver state senators, little enough that nobody would bother melting the coin. Congress also suspended mint marks from 1965 through 1967 so that collectors could not sort the new coins by facility and hoard them. Regular proof sets were shelved for those same three years and replaced by Special Mint Sets struck at San Francisco with no mint mark at all, the 1965 set actually produced during 1966. Mint marks returned in 1968, this time on the obverse.
None of it worked. By 1968 nearly every silver clad half had vanished from circulation anyway, pulled out by the same speculation the Act was written to stop. President Nixon signed the legislation that ended silver in the half dollar on December 31, 1970, and the 1971 coins came out as plain copper nickel.
How to tell one apart in hand
Sorting 40% silver half dollars out of a jar starts with the date, because the date does almost all the work. 1964 is 90 percent. 1965 through 1970 is 40 percent. 1971 and later is clad, with the exception of modern silver proof coins that were sold in sets and never circulated.
- Look at the edge. A copper nickel half shows a bright orange copper stripe running around the rim. A silver clad half shows a duller gray edge, sometimes with a faint warm line, never that clean band of copper.
- Weigh it. A scale reading to a hundredth of a gram separates all three eras cleanly: 12.50, 11.50, 11.34.
- Watch the Bicentennials. Halves dated 1776-1976 are mostly clad. The 40 percent silver Bicentennial coins came only in collector sets and carry an S mint mark.
The edge test is the one to trust in poor light. Wear dulls a coin’s color and tone fools people, but the copper core either shows a stripe or it does not.
The other coins struck in 40 percent silver
The Kennedy half was not alone. The Eisenhower dollar was issued in 40 percent silver at San Francisco in 1971 through 1974 and again in 1976, sold to collectors rather than released into circulation. Those coins weigh 24.59 grams and hold 0.3161 troy ounces of silver. Uncirculated pieces came in blue envelopes and picked up the nickname Blue Ikes; the proofs shipped in brown faux wood grain boxes and became Brown Ikes. The packaging is still how most dealers sort them.
For the Bicentennial, Public Law 93-127 called for 40 percent silver versions of the quarter, half dollar and dollar, with at least 45 million specimens struck so that ordinary buyers could get them. The Mint announced public sale of the three piece proof and uncirculated sets on January 26, 1976. Those sets are the reason a 40 percent silver quarter exists at all, since no silver quarter was struck for circulation after 1964.
Where 40% silver half dollars fit for a holder
They do two different jobs, and the honest answer depends on which one you want.
As metal, 40% silver half dollars are junk silver with a smaller number attached. They behave like silver, they divide well, and they are as recognizable as any American coin. Because fewer buyers bother learning the 0.1479 figure, the market for them tends to be a little thinner than the market for 90 percent coin, which usually shows up as a lower premium over metal value going in and a lower one coming out. That cuts both ways depending on which side of the trade you are on. With silver trading near $63 an ounce in mid September 2026, the metal value of a stack of these is real money, but it is a floor and nothing more.
As collectibles, a few dates stand apart. The 1970-D is the key to the run at 2,150,000 pieces, and it was issued only in that year’s mint sets, a limitation the Mint never publicized. The 1967 business strike sits at the other end at 295,046,978. The Special Mint Set coins from 1965 through 1967 and the 1968-S and 1970-S proofs are plentiful enough to be affordable, but they are graded and traded as numismatic items, not as metal. If one turns up in a jar, do not throw it in the sell pile by weight.
The practical habit is the same one that serves for any Franklin half or Walking Liberty that comes out of an estate. Sort by date before you sort by anything else, count face value rather than coins, then convert to ounces. The arithmetic is identical to the one used on Mercury dimes, only the constant changes. You can see how we think about metal value and market structure in how it works and in our rules of gold, and you can browse what is currently listed in the coin catalog.
Silver clad halves are the awkward middle child of American coinage, born of a compromise that satisfied nobody and disappeared from pockets anyway. That history is exactly why they still turn up in drawers sixty years later, and why knowing one figure, 0.1479, is worth more than any guess about what a jar of halves is worth.
