PART VI. Striking Errors:
Multiple strikes:
In-collar/out–of-collar
Definition: Multiple strikes can occur inside the collar or outside the collar.
A 1998 Lincoln cent double struck in-collar with 90 degree rotation between strikes.
Definition: Multiple strikes can occur inside the collar or outside the collar.
A 1998 Lincoln cent double struck in-collar with 90 degree rotation between strikes.
Definition: Multiple strikes can be either on-center or off-center. The reasons for multiple strikes are as varied as the number of strikes that can occur. Ejection failures which prevent a planchet to correctly discharge from the striking chamber are numerous.
A 1985 10 pesos from Argentina which has been struck off-center a minimum of 17 times. This coin was highly distorted by several other planchets entering the striking chamber. Complete details of each strike were obliterated by these intruding planchets.
Definition: The presence of two or more misaligned strikes on the same face of the same coin. The position of the affected die can be stable or quite unstable.
It is rare for a coin to be struck more than once by a misaligned die. It is even rarer for those strikes to be well-separated as the result of die instability. This undated India 10 rupees coin (2019 – present) features a 31% off-center first strike and a series of at least six additional off-center strikes that were all 79% off-center. The hammer die was properly centered during the first strike. However, during the later off-center strikes, the hammer (obverse) die became progressively more misaligned until it finally migrated beyond the coin. The coin showed very little movement during those later strikes and the anvil die remained fixed in position.
Definition: After a centered first strike, the hammer dies tilts down at one pole and strikes the coin a second time at an angle. The result is that one pole is extremely well-struck on both faces while the opposite pole shows little or no trace of the second strike.
The illustrated 1976 Israel Greeting medal was minted by the Israel Government Coins and Medals Corporation, a quasi-public entity that produces all of Israel’s coins and medals. The first strike was quite weak, but was centered. The second strike was delivered at an angle of approximately 45 degrees.
This medal shows both a vertical misalignment (tilted die error) and a 50% horizontal misalignment of the hammer die. The hammer die started shifting position immediately after reaching the lowest point of its downstroke during the first strike. As a result, newly-struck letters in the northwest quadrant were badly scraped.
Vertical misalignments of greater than 15 degrees are almost always accompanied by a horizontal misalignment. This is because when a die tilts down at one pole, it also swings in, unless there is compensatory lateral movement of the die or die assembly in the opposite direction.
Definition: This error occurs when the coin is struck at least twice with one of those strikes showing a rotation of either the hammer or the anvil die.
On rare occasions a double-struck coin will show that one of the dies (almost always the hammer die) rotated between strikes. Such errors are most common on proofs from the late 1960’s and early 1970’s. This 1966 nickel shows a rare business strike with such an error. The hammer (obverse) die rotated about 15 degrees between the
first and second strike. This coin comes courtesy of Thomas Barosko.
Definition: This error occurs when a coin is struck at least twice and the subsequently strikes shows an offset in direction.
A horizontal, vertical, pivoted, or rotational misalignment can occur on the second strike after a normal first strike. It’s also possible for a misaligned die strike to precede a normal second strike, although this has only indirectly been documented through clash marks.
In this 1999 cent, the hammer (obverse) die was centered during the first strike. Between the first and second strike, it shifted to the right about 10%. Before the hammer die descended a second time, an unstruck planchet intruded into the striking chamber, leaving an indent on the left side. Details of the first strike can be seen in the floor of the indent. The second strike also shows a partial collar error
Definition: This error occurs when a newly-struck coin fails to properly eject from the striking chamber and is struck several more times by the same die pair. A multi-struck error of this nature can occur inside or outside of the collar.
This 2000P Sacagawea dollar coin was struck 6 times. The first strike appeared to be normal, while the remaining five strikes were delivered off-center. The coin moved slightly between each off-center strike.
Images are courtesy of Heritage Auctions.
Definition: Most multi-strikes show the same face struck repeatedly. Coins that flip over between strikes are rarer.
The 1935 Lincoln cent shown below is an in-collar, flipover double strike. After a normal first strike, the coin flipped over and landed back inside the collar. It was then struck a second time.
The 2000 Lincoln cent shown below was first struck off-center. It then flipped over and was struck a second time
even farther off-center. The second strike is uniface (struck against another planchet).
Definition: A counterbrockage is an expanded and distorted image (raised and normally-oriented) that is generated when a brockaged coin is struck into a planchet.
A single counterbrockage is rare enough, but the 2007 India 1 rupee coin shown below is a double counterbrockage of the reverse design on the reverse face. Detailed images with companion information as to how this double counterbrockage may have occurred is further below.
As with most 1 rupee coins, the reverse face was struck by the hammer die.
First, here are two images with the left being our double counterbrockage and the right being a normal 1 rupee coin.
Directly below are three images with the counterbrockage design elements labeled on the left half of the coin. Features of uncertain status are labeled with a question mark.
A close-up of the right side of the reverse showing the two upraised thumbs. The more peripheral thumb is larger and clearer. The curled fingers 2-5 can be faintly discerned down and to the left of the thumbs.
A close-up of the two versions of “RUPEE” (the smaller one very faint) and the Sanskrit letters above them.
With respect to the thumb and the word RUPEE, these more peripheral design elements are larger and more distorted than the versions that lie closer to the center of the coin. The puzzling thing is that these more peripheral elements are also clearer than the more centrally located ones. Ordinarily, the more expanded a counterbrockage is, the less clear it is.
There are at least four scenarios that can be invoked to explain the appearance of this coin. None assumes more than one strike.
Scenario 1. The coin that created the counterbrockage was, itself, struck against a double-struck rupee. That would have left a double brockage of the reverse design on the obverse (bottom) face of the coin. The problem with this scenario is that both sets of design elements should be the same size and one set (representing the earliest strike) should be decidedly incomplete.
Scenario 2. The coin that created the counterbrockage could have been double-struck against a single 1 rupee coin, with movement between each strike. The problem here is that there is too much spread between “primary” and “secondary” counterbrockage design elements and the spread is radial, rather than offset.
Scenario 3. The coin that created the counterbrockage could have been double-struck against two different 1 rupee coins. This is highly unlikely, given the close association between “primary” and “secondary” counterbrockage elements. There is also little chance that two different coins would have been so perfectly placed beneath the coin that would eventually generate the counterbrockage.
Scenario 4. This is by far the most complex scenario, but it has much to recommend it. It entails four steps.
Although Scenario 4 is quite complicated, it fits the facts better. Regardless of its accuracy, what IS clear, is that a very complicated chain of events must lie behind the creation of this wonder of an error.
Definition: Machine Doubling is the product of die instability and displaced energy from the original strike that involves either a die rebounding off of the surface of the coin; or from a shift or turn of a die after the initial strike. The resulting impact largely affects struck devices on the coin. In its rudimentary form it is very common. In the extreme it can grossly distort devices or in some cases mimic a double strike. The doubling can also become tripling or quadrupling if the energy of the original strike rebounds and returns multiple times. Also called: machine doubling damage, machine damage doubling, mechanical doubling, strike doubling, shift doubling, ejection doubling, shelf doubling, shear doubling and field doubling.
Machine doubling can in one direction rebound more than once. Below are two examples of machine tripling; the first on a Lincoln memorial cent and the second on a Jefferson nickel reverse. In the case of the Lincoln, most of the motto displays machine doubling, whereas the ES and a fragment of the T show localized machine tripling.
The image to the right shows a D mintmark on a 1936 Washington quarter. Two things that are unusual about this anomaly are, first it is isolated machine doubling. No other design element near the mintmark shows any signs of machine doubling. This isolation may be caused by the mintmark being a bit higher (sunk deeper into the die) than the surrounding design elements and more prone to being “hit” by the retreating die that causes this anomaly.
Careful examination of this machine doubling shows at least three different steps or “hits”. Two actions may have caused this phenomena; a chattering anvil die or a resonating coin.
Like any solid material, a coin will vibrate or resonate at a certain frequency when struck. In that very brief moment that the coin does come into the second contact with a die, the vibrations generated by the coin will cause the multiple steps of machine doubling to occur with just one contact of the coin to the die.
Image is courtesy of Ed Nieko