Definition: The collar is ringed shaped and considered to be the third die. Its purpose is to cease the exapantion of the metal from the newly struck coin. It can have a reeded or plain surface.
Definition: Here an entire segment of the collar’s working face (or hardened lining) breaks away, leaving a void that begins and ends quite abruptly. A key diagnostic for a full collar break is a “step-up” at both endpoints. The step marks the transition from the normal portion of the edge that shows collar contact to the area where coin metal was free to expand.
This 2000-D nickel depicted below is a stellar example of a complete collar break. About 100 arc degrees broke away, allowing the coin metal to flow into the resulting void. Both die faces show heavy die damage. The damage could be from fragments of the collar, or could indicate that both the collar and the dies were damaged by foreign matter that entered the striking chamber. Another sweet bonus is the small second strike that interrupts smooth convexity of the collar break at 1:00.
Because the gap in the collar was considerably smaller than 180 degrees, the planchet had no choice but to settle against the intact side of the collar. But this is not always the case, especially when the gap in the collar equals or exceeds 180 degrees
Definition: Bits of the collar can chip off, either spontaneously or as the result of impacts. Collar chips are recognizable on the edge of the coin as small, raised defects. Their appearance differs between smooth-edged and reeded issues. In smooth-edged issues, collar chips typically extend down from the rim struck by the hammer die but seldom reach the opposite rim. In reeded issues they are always vertically oriented and often extend from one rim to the other.
Double-struck 1982 cent with die dents and impact scars on both faces. Two large, contiguous collar chips on the edge extend from 11:00 to 2:00.
Close-up of the two collar chips showing how they extend down from the obverse rim (center image).
The above images show collar breaks on 1960 D small date Lincoln cents.
Sometimes a collar splits at opposite poles and spreads apart. This produces a coin with two raised nibs at opposite poles and with a diameter that’s greater than normal along an axis that is oriented 90 degrees to the meridian that connects the two nibs. Signs of collar contact exist on either side of each nib, indicating the collar is still intact. Usually collar contact is visible even at the poles that lie at right angles to the nibs, although this might be a bit hard to discern on smooth-edged issues.
Depicted below is a 1964-D nickel with an impressive bilateral split collar. The planchet landed midway between the sides of the spread-out collar.
Close-up of the nib located at 11:00.Close-up of the nib located at 5:00.
Definition: The inverted die setup employs the obverse die as the anvil die. This setup has been used sporadically over the last 200+ years and was slowly re-introduced in the last decade of the 20th century. The inverted setup is mainly associated with the high-speed Schuler press, although exceptions exist. Until recently, the earliest modern examples of coins struck with the inverted setup were a few 1992-D quarter dollars. Recently, a 1989-D quarter dollar struck with the inverted setup was recognized. It may represent an informal or even unauthorized test of the setup, as discussions on “changing the orientation of the reverse die in presses” don’t appear in the annual Mint report until fiscal year 1990.
Several clues tell us that this 1989-D quarter was struck with inverted dies:
(1) The reverse design rim is far better defined and far more complete than the obverse design rim. (2) Signs of collar contact appear along the edge of the unstruck obverse crescent. (3) The reverse shows four single-downstroke strike lines (numbered on close-up image). Multiple strike lines produced by a single downstroke are known only on the face struck by the hammer die.
Definition: A form of widely offset, raised doubling that appears on the face struck by the anvil die.
The term “ejection doubling” was traditionally applied to minor smearing of the design generated by the anvil die. The idea was that the newly-struck coin resisted being pushed off the anvil die face by the ejector, causing the raised design elements to catch on the edges of the die’s recesses.
Since traditional ejection doubling is indistinguishable from minor slide doubling (a form of machine doubling), it was retired from use. Slide doubling results from lateral movement of either die at their moment of closest approximation or just as the hammer die is lifting off the surface of the coin.
In 2022, ejection doubling was resurrected and applied to widely offset raised doubling that is not smeared and that appears on the face struck by the anvil die. The distance between primary and secondary design elements is too great to represent push doubling (another form of machine doubling) because the amount of play available between anvil die and collar is insufficient.
James Hitchcock discovered the 2008-P 5-cent “type specimen” that has been used to define this new form of doubling to which the old moniker “ejection doubling” has been applied.
The doubling appears on the obverse face, which was struck by the anvil die. A secondary, right-positioned eye is located 0.5 millimeters below the normal eye. The primary eye also shows close doubling that would have been classified as push doubling had the more distant eye not been present.
The gap between the primary eye and the distant secondary eye is too great to be explained by the recoil and lateral shift of the anvil die within a fixed collar. There are at least two possible explanations:
It’s possible that, once the coin was pushed up out of the collar, both the anvil die and the collar shifted southward at the same time that the anvil die was recoiling from, and returning to, the coin’s reverse face. Delayed retraction of the hammer die may have been necessary to maintain resistance to the impact of the anvil die.
The newly-struck coin adhered to the hammer die face and was carried along as the hammer die bounced upward, shifted laterally, and sank downward again. This allowed the lower face of the coin to make light, secondary contact with the anvil die. This scenario requires the coin to be free of the collar’s embrace but does not require movement of the anvil die or collar.
Definition: The unauthorized presence of initials or symbols tucked into a design. These are added to a working die or master die without the knowledge or approval of mint management. They are carved out or punched in by a mint engraver or other artisan. Several examples are known from Mexico, which has a long tradition of such clandestine flourishes. For example, some 1984 1 peso obverse working dies carry the tiny cursive letters “Ra” (for Rodolfo Alvarado or Rodolfo Alvarado Flores) within the collar of José Maria Morelos.
This 1974 bronze Mexico 20 centavos features a tiny engraver’s insignia “V̇” in one of the cactus pads on the reverse face. It was designed to resemble the triad of cactus spines that it replaced. The symbol is reportedly the initial of the engraver Ricardo Luna Vasco. Since this symbol seemingly appears on every 1974 20 centavos, Vasco would have altered the master die for this year. Vasco’s insignia reportedly appears on at least some working dies belonging to several other denominations, including the 10 centavos (1974 – 1976), 50 centavos (1975 – 1976), 1 peso (1974 – 1976), and 5 pesos (1974, 1976, 1977).
The working reverse die that struck this 1973 20 centavos has an inverted L and the back of a correctly-facing R hidden with the saguaro cacti. They are said to have been placed there by, or in honor of, the engraver Lorenzo Rafael.
Definition: A saddle strike in which the hump or saddle buckles toward the reverse die.
In almost all saddle (tandem) strikes, the unstruck interval between the two off-center strikes buckles toward the hammer die, which is usually the obverse die in such errors. Buckling toward the reverse die can be an indicator of an inverted die setup (reverse die as hammer die). In cents, this is a factor only for those struck after after 1996 (or possibly 1995). The earliest unmistakable evidence for cents being struck with inverted dies appears in 1997. Inverted dies appear earlier in other denominations (as early as 1992 quarter dollars). At least one indisputable example of a saddle-struck cent generated by inverted dies is known (a quad-struck 2000 cent).
The other reason for buckling toward the reverse die is a rare reversal of the usual tendency. In other words, and for unclear reasons, the hump will bulge toward the anvil die. This reversal of the usual hump direction presumably depends on the collar being in an unusually depressed position; otherwise, it will impede the growth of the hump.
This rather battered, undated cent shows a hump pointing in the direction of the reverse die. In the absence of a date or any indicator of collar location, it’s impossible to say whether the inverted hump indicates an inverted die setup (reverse die as hammer die) or a rare instance of warping in the direction of the anvil die. Both faces of each off-center strike display roughly-textured struck-through areas.
This saddle-struck quarter dollar shows a hump that points toward the reverse die. The relatively high relief and lack of detail of Washington’s head indicates it was struck long before the modern introduction of the inverted die setup. It was most likely struck in the San Francisco Mint between 1965 and 1967. Other saddle-struck quarters from this same time period show a hump that points toward the obverse die. So it’s likely that the inverted hump on this specimen is due to a rare instance of warping toward the anvil die. Very few saddle-struck quarter dollars are known, and they may represent a short-lived experiment in adapting a dual or quad press for a denomination larger than a nickel.
Definition: Reeding prolongations generated as the newly-struck coin is pushed up and out of the collar. The reeding extensions always point toward the face struck by the anvil die. They stick up vertically from the junction between the design rim and the edge, forming set of sharp prongs that look like a picket fence or the battlements of a castle. It’s not clear why crenellations form or why they occur so rarely.
Crenellations appear on the reverse rim of this 1976-D quarter dollar.
Definition: A brockage generated by a large dropped filling. Such errors occur when a large flake of die fill separates from one die and falls onto, or attaches itself to, the opposite die. Such brockages can also occur when a large flake of die fill flips over onto a planchet. Normally-oriented incuse impressions of large, multi-element dropped fillings are rare; mirror-image incuse impressions (brockages) of multi-element dropped fillings are even rarer.
This 1993 cent features an in-collar, first-strike brockage of the obverse design on the reverse face. This error began when a large flake of die fill fell from the hammer (obverse) die onto the anvil (reverse) die when a planchet failed to be fed into the striking chamber. The flake could also have been directly transferred to the anvil die during a clash. The next planchet that was fed into the striking chamber (this coin) landed on top of the dropped filling and the two were struck together, generating the brockage.