Indent (IND)

An indent error occurs when two planchets overlap in the striking chamber and one is pressed into the other during the strike. The overlapping planchet leaves a circular, featureless depression on the coin beneath it — a smooth, dish-shaped area matching the diameter and shape of the intruding planchet. The indented coin retains its normal design in the area that was directly struck by the die, but the portion covered by the second planchet shows only a blank, pressed-in surface with no design detail.

Indents are closely related to brockage errors, but with one key distinction: in a brockage, the overlapping piece is a previously struck coin that transfers its design into the planchet. In an indent, the overlapping piece is an unstruck planchet (or the blank side of a partially struck coin), leaving only a featureless depression.

How Does It Happen?

The automated feeding system in a modern coin press delivers individual planchets into the collar between the dies at rates exceeding 750 planchets per minute. At these speeds, feeding errors are inevitable, and double feeds — where two planchets enter the striking chamber simultaneously — are one of the most common causes of indent errors.

The mechanics of an indent unfold as follows:

1. Double feed: Two planchets enter the striking chamber at the same time. One sits properly in the collar (or close to it), while the second sits on top, partially overlapping the first.
2. The dies close: The hammer die descends with full force. The lower planchet receives a direct impression from the lower die, but the overlapping area is blocked by the upper planchet, which absorbs the striking force in that zone.
3. Impression transfer: The upper planchet is pressed into the lower planchet's surface, creating a circular depression. Because the upper planchet is a blank disc with no design, the depression is smooth and featureless.
4. Both coins eject: The lower coin emerges as an indent error. The upper coin, having received a partial strike from the hammer die on one side and having been pressed against the lower planchet on the other, becomes an off-center strike or partial brockage depending on its positioning.

The depth and clarity of the indent depend on how much the two planchets overlapped and how much striking pressure was transmitted through the upper planchet. A planchet sitting nearly centered on top of another produces a large, deep indent covering most of the lower coin. A planchet barely overlapping the edge produces a small, shallow crescent-shaped indent.

How to Identify an Indent

Indent errors have several distinctive diagnostic features:

• Circular depression: The indent is a smooth, round depression whose curvature matches the diameter of the planchet that caused it. On a Lincoln cent indent, the depression has the curvature of a 19 mm circle.
• Featureless surface: The indented area shows no design detail — it is a smooth, blank depression. This distinguishes an indent from a brockage, which shows a mirror-image design impression in the depression.
• Normal design in the unaffected area: The portion of the coin that was not covered by the overlapping planchet shows a normal, fully struck design with proper detail.
• Sharp boundary: The edge of the indent typically shows a sharp, defined border where the overlapping planchet's rim was pressed into the coin's surface.
• Metal flow at the edges: Around the perimeter of the indent, the coin's metal may show slight distortion or flow marks where the striking pressure pushed metal toward the depressed area.

Same-Denomination vs. Wrong-Denomination Indents

Most indents are caused by a planchet of the same denomination as the struck coin — a cent planchet indenting another cent, for example. These same-denomination indents show a depression matching the host coin's diameter.

Wrong-denomination indents occur when a planchet intended for a different denomination enters the striking chamber. A dime planchet sitting on top of a cent planchet in the cent press produces an indent with a smaller diameter circle (17.9 mm dime blank on a 19 mm cent). These cross-denomination indents are scarcer and more valuable because they require two feed system errors — a wrong planchet entering the wrong press and overlapping another planchet during the strike.

Notable Examples

Cent-on-Cent Indents

Lincoln cent indents are the most common and affordable examples of this error type. The high production volume of cents ensures that double feeds occur regularly. Cent indents showing 25% to 75% coverage, with the date and mint mark visible in the unaffected area, are the most popular with collectors.

Quarter Indents

Indented Washington quarters are significantly scarcer than cent indents. The Mint exercises tighter quality control on quarter production, and quarters pass through more inspection points before release. An indented quarter with a large, deep depression and a visible date commands a strong premium.

Multi-Denomination Indents

Among the most prized indent errors are those involving planchets of different denominations — a dime planchet indenting a quarter, or a cent planchet indenting a nickel. The size mismatch between the indent depression and the host coin makes the error immediately obvious and confirms that two different denomination planchets were present in the press simultaneously.

Double and Triple Indents

On rare occasions, three or more planchets overlap in the press, producing a coin with two or more indent impressions. These multiple indents create overlapping circular depressions on the coin's surface and are substantially rarer than single indents.

Foreign Planchet Indents

A small number of indent errors have been attributed to foreign planchets — blanks intended for coins of other countries that were being struck at the U.S. Mint under contract. These foreign-planchet indents are recognizable by their non-standard size and are among the most unusual indent varieties.

Collecting Tips

• Coverage percentage matters: Indents are described by the approximate percentage of the coin's surface covered by the depression. Moderate indents (25-60%) that leave the date and mint mark visible are the most desirable balance of visual drama and identifiability.
• Depth adds value: A deep, clearly defined indent is more valuable than a shallow, barely perceptible one. The depth reflects the amount of striking pressure transmitted through the overlapping planchet.
• Date visibility is critical: As with off-center strikes, indents that preserve the date in the unaffected area are worth substantially more than those where the date falls within the indented zone, because the date allows attribution to a specific year.
• Look for the companion coin: Every indent error produces a companion piece — the overlapping planchet that caused the indent, which itself becomes a partial brockage or off-center strike. Matched pairs of an indent and its companion are extraordinarily rare and valuable.
• Wrong-denomination indents carry strong premiums: When the indent depression does not match the host coin's diameter, it confirms a cross-denomination feed error, adding significant value.
• Authentication through PCGS or NGC: Grading services attribute indent errors on the holder label and note the approximate coverage percentage. Encapsulation provides authentication and protects these often-delicate coins from further damage.

Related Error Types

• Off-Center Strike (OFC) -- Planchet mispositioned in the press, producing partial design
• Broadstrike (BRD) -- Coin struck without the collar die in place
• Multi-Strike (MST) -- Coin struck multiple times by the dies
• Capped Die (CPD) -- Struck coin sticks to die and caps subsequent strikes
• Struck on Wrong Planchet (WPL) -- Coin struck on a planchet intended for a different denomination