Floating Die Clash (FDC)
A floating die clash is a clash between a die and a loose fragment of a broken die. Error-Ref defines it as an error "generated in the aftermath of a die break": the broken-off fragment stays in the striking chamber, a die strikes its working face, and the fragment's design is transferred to that die. Every coin struck afterward carries pieces of design in a place where they make no sense, which is why the clash is called "floating." It is not the same as an ordinary clash between two misaligned dies; that is a horizontally misaligned die clash.
How Does It Happen?
In a normal die clash, the two working dies meet without a planchet between them and each picks up part of the other's design. A floating die clash needs a broken die first:
- A die breaks: A piece breaks away from one of the dies. On the coins, the broken die then strikes a cud where the piece is missing.
- The fragment stays in the press: Instead of falling clear, the fragment remains in the striking chamber.
- A die strikes the fragment: Error-Ref notes that usually one of the dies is protected by a planchet. If the other die hits the working face of the fragment, the fragment's incuse, mirror-image design is pressed into that die, where it becomes raised and normally oriented.
- Later coins carry the transfer: Every coin struck afterward by the damaged die shows those design elements incuse and mirror-image, in an unpredictable location.
The transfer can go into the intact die of the pair or into the intact part of the die that broke. Error-Ref notes that most floating die clashes are restricted to the field, because that is the part of the die face most easily damaged.
Error-Ref calls a clash made by a fragment from one of the coin's own dies "endogenous" and knows of around half a dozen. It records a single "exogenous" floating die clash, from a fragment of some other die: the reverse of a 1972-D cent discovered by Robert Piazza, showing the outline of the fragment's field and the tops of two letters that may be the AM of AMERICA.
How to Identify a Floating Die Clash
The primary diagnostic is design that does not belong where it sits:
- Out-of-place design: Part of a design shows in a location no normal or misaligned clash could put it, often in the field.
- Incuse and backwards: The transferred elements are sunk into the coin and mirror-image, because the fragment's design was impressed into the die and then struck into the coin.
- A cud on the same die pair: An endogenous floating clash goes with a die break. Look for a cud, the raised blob struck by the broken area, on one face of the coin.
- Repeats on later coins: Like any clash mark, the floating clash is in the die, so it appears in the same place on every coin struck after the event.
- Only part of a design: A fragment carries only a piece of the die face, so the transfer is usually a few letters, a section of rim, or part of a device, not a whole outline of the opposite side.
Floating Die Clash vs. Other Clash Types
| Diagnostic | Floating Die Clash | Typical Die Clash | Horizontally Misaligned Clash |
|---|---|---|---|
| What hit the die | A broken die fragment | The opposing die, aligned | The opposing die, shifted sideways |
| What transfers | Part of the fragment's design | The opposing design, in register | The opposing design, shifted |
| Where it lands | Unpredictable, usually in the field | Where the designs overlap | Shifted in the direction of the misalignment |
| Usual companion | A cud on one of the dies | None | None |
Notable Examples
1972-D Lincoln Cent (Exogenous)
The only exogenous floating die clash Error-Ref knows of, on the reverse of a 1972-D cent. The fragment did not come from either of the coin's dies; it may have come from a neighbouring press or from an earlier die that broke and was replaced.
1974 Lincoln Cent
Error-Ref illustrates a 1974 cent into which a fragment of its own obverse die was struck and retained. The impact between the fragment and the intact part of the die produced a floating die clash, which appears on every cent the damaged die struck afterward.
MadDieClashes Listings
The die clash reference site MadDieClashes.com, edited by Jason Cuvelier and Mike Diamond, numbers floating die clashes separately (FDC). Its examples include Lincoln cents of 1972-D, 1974, 1987, 1989 and 1993, and Jefferson nickels of 1979 and 1983.
Collecting Tips
- Look for the break: Because a floating clash follows a die break, check both faces for a cud or other die damage that explains where the fragment came from.
- Don't confuse with a misaligned clash: A shifted outline of the opposite side's design is a misaligned die clash, not a floating one. A floating clash carries only a piece of design, and usually sits in the field.
- Compare to a normal coin: Use a normal coin of the same type to work out which design the stray elements came from and whether they are mirror-image.
- Reference documentation: Check MadDieClashes.com and Error-Ref for catalogued floating clashes. A documented reference supports attribution.
- Photography technique: Use low-angle directional lighting to reveal faint incuse clash marks, and photograph the affected coin beside a normal one.