Brockage Error Coins

Specifications

Denomination: multiple
Series: Mint error types

A brockage is a coin struck against another already-struck coin instead of a die, leaving a mirrored, sunken (incuse) copy of the design on one face. Clear full “mirror brockages” are scarce and can sell for substantial money — but the two clues you must confirm together are mirrored AND incuse.

Mudskippie / Wikimedia Commons, public domain — released by copyright holder

What it is

A brockage is a coin struck against another already-struck coin instead of a die face, leaving a reversed, recessed (incuse) copy of the design on one face.
It is a striking-stage error: the planchet and dies are fine — the failure happened in the moment of striking.
If the stuck coin adhered to the lower (anvil) die it produces an obverse brockage; stuck to the upper (hammer) die, a reverse brockage. (Wikipedia; accessed 2026-09-17)
A full brockage covers the entire face, while partial brockages cover only part. The very first impression is the first-strike brockage; if the stuck coin stays on the die it becomes a die cap and strikes additional planchets, producing early-stage, mid-stage, and late-stage brockages that grow progressively weaker. (Wikipedia; accessed 2026-09-17)

How it happens

A struck coin fails to eject and stays in the press, stuck to one of the dies.
The next planchet feeds in and is struck against the stuck coin instead of the die face.
The stuck coin’s raised design presses a reversed, recessed copy into the new coin. (Wikipedia; accessed 2026-09-17)
If the stuck coin stays on the die, it becomes a die cap and strikes additional planchets — each successive brockage comes out progressively weaker as the cap distorts. (Wikipedia; accessed 2026-09-17)
Brockages were common in hammered coinage, largely restricted to obverse brockages because a worker would usually notice a coin stuck in the reverse anvil die — and a noticed brockage could simply be restruck. Screw presses from the mid-16th century onward drastically reduced escaping brockages, but high-speed machinery in the 19th century brought more of them. (Wikipedia; accessed 2026-09-17)
It is also documented that some unscrupulous mint workers deliberately created brockages to sell to collectors. (Wikipedia; accessed 2026-09-17)

How to identify

Confirm BOTH clues: the design must be mirrored (backward) AND incuse (sunken). Raised backward lettering points elsewhere.
Backward lettering describes orientation; incuse describes depth — confusing the two leads investigations astray. (CoinHub; accessed 2026-09-17)
A brockage does not have to cover the whole face — partial brockages are genuine; record the actual affected area.
Don’t confuse a brockage with a capped die: the cap is the coin stuck to the die; the brockage is the later coin struck against it.
Good practice is to photograph both faces and the edge under changing light, keep the original images labeled by side, and never mirror a photo file during comparison, since mirroring destroys one of the very features being checked. (CoinHub; accessed 2026-09-17)
A photograph alone does not authenticate the error. (CoinHub; accessed 2026-09-17)

Real error vs. post-mint damage

Contact marks and other post-strike damage can leave brockage-like impressions. A genuine brockage is struck, so metal flow looks natural; pressed or scraped imitations show disturbed surfaces. (CoinHub; accessed 2026-09-17)
Reversed-looking detail is only an observation, not proof — and PCGS draws a firm line between mint errors and later damage or alteration, so a meaningful premium calls for professional error attribution. (CoinHub; accessed 2026-09-17)
Never squeeze two coins together to “test” or create a comparison piece — that is damage, not diagnostics.
Mated pairs (a die cap plus a brockage it struck) exist but are rarely found together; don’t pair unrelated odd coins by date or color.

Notable examples

Undated Indian Head cent with a full early-stage brockage of the reverse design on its obverse. (error-ref, via Heritage Auctions; accessed 2026-09-17)
198X-P Jefferson nickel, 30% brockage on a 40% off-center strike, graded PCGS MS66. (CoinHub, via PCGS TrueView; accessed 2026-09-17)
Among modern coins from industrialized mints with strict production control, brockages are relatively rare, and coins in good condition with a clear brockage are collector’s items that can sell for substantial amounts. (Wikipedia; accessed 2026-09-17)

What drives value

The most desirable are the sharpest, most complete first-strike “mirror brockages,” which form when both the brockage-maker coin and the planchet are confined by the collar. (Wikipedia; accessed 2026-09-17)
Severity (full vs. partial), condition, and grade — a clear full brockage in high grade commands the strongest premium.
Denomination and collector demand for the series matter as they do for any error.
Honest floor: weak, partial, or damaged brockage impressions are far less desirable, and anything that cannot be distinguished from post-strike damage carries no error premium at all — get professional error attribution before paying real money. (CoinHub; accessed 2026-09-17)