PART V. Planchet Errors:

Bi-metallic Errors:

Ring Incomplete Punch

Definition: Bi-metallic error coins are restricted to foreign countries. These coins may experience any of the many types of striking errors listed in the Error-Variety Ready Reference however, one must understand we are dealing with two components, a ring & a core. Any number of exotic possibilities or combinations of die varieties, die errors, planchet errors & striking errors can be found on bi-metallic coinage.

A 1996 Canadian polar bear two dollars. While the center hole is clearly misaligned, there was an unsuccessful attempt to punch the ring either the first or second time. Punch scaring is evident on both obverse & reverse face (black arrows indicate punch scaring).

PART VI. Striking Errors:

Bi-metallic Errors:

Wrong Ring

Definition: Bi-metallic error coins are restricted to foreign countries. These coins may experience any of the many types of striking errors listed in the Error-Variety Ready Reference however, one must understand we are dealing with two components, a ring & a core. Any number of exotic possibilities or combinations of die varieties, die errors, planchet errors & striking errors can be found on bi-metallic coinage.

Occurs when a normal core is joined with a wrong ring. These errors are unequivocally rare.

A two pound Technology from Great Britain. Ring is strongly attracted to a magnet (steel ring). The ring also has a misaligned center hole. The ring is much thinner than the core resulting in the near incomplete absence of design transfer on either face of the ring. The ring also sheared & snapped when struck.

A two pound 2007 Gun Powder Plot from Great Britain with wrong ring. The ring also has a misaligned center hole. The ring is thinner than the core resulting in the absence of some design transfer on either face of the ring.

Crescentic plateau emerges from Proof polishing

mishap

By Mike Diamond | Jan. 31, 2011 9:00 a.m. 

Obverse face of a 2009-S Northern Mariana Islands quarter dollar exhibits a raised crescent at its northern pole. It appears to represent a mishap during polishing of the field after the frosted texture was applied to the design.

When Clair Alan Hardesty received his 2009-S Proof set, he immediately saw that something was wrong with his Northern Mariana Islands quarter dollar. A thin, bright line could be seen arcing across the obverse face, cutting through the legend united states of america. The end-points of the line coincided with the inner margin of the design rim and extended from a point above the t of united to the e of america.

Recognizing it as a probable die error, Hardesty sent the coin to PCGS under their Mint error service. The response was disappointing and confusing. A customer service representative informed Hardesty that the grader had determined that “this is not an error coin. They are as struck.” Hardesty insisted that they look again, and the second response was similar, “The coin was re-evaluated for the error a second time. The information you provided was taken into account. Unfortunately the graders did not feel it was an error.”

Undeterred by the failure of PCGS to recognize a grossly obvious flaw, Hardesty sent the coin tome for analysis. Upon receiving the coin I immediately agreed that this is a significant die error. We next had to determine what kind of die error we were dealing with.

The bright arc is actually a sharply defined step. The crescentic area demarcated by the step is raised above the rest of the field. This indicates that the corresponding field portion of the die was recessed. The field has a mirror-like Proof finish above and below the step. However, faint radial ripples distort the surface of the abnormally polished crescent.

How was recess formed?

The question now turned to how this recess formed. A die dent seemed unlikely as this would have probably dulled the finish. A major clue as to what transpired can be found in the letters that cross the step. Above the step the letters are narrowed or constricted. This is most evident in the letters sta of states and the word of. Thinning of design elements is caused by only one thing — mechanical removal of the field surrounding each design element. As the field is lowered on the die face, the letters get narrower. This is because the sides of each letter converge as you go deeper into the die face.

The available evidence indicates that the step and recessed crescent were caused by a mishap in polishing the die face to a mirror-like finish. Die polishing is the exclusive province of Proof dies and dies that strike collector issues, like the coins in the Special Mint sets issued from 1965 to 1967. The intent is to create a highly reflective surface on the die and on the coins it strikes. If taken too far, this process can cause thinning of design elements and loss of details in the lowest parts of the design.

Die polishing of this sort should not be confused with intentional die abrasion designed to remove clash marks and other forms of die damage. Primarily applied to circulation-strike dies, such salvage attempts typically leave lots of die scratches and certainly don’t produce a mirror-like finish. The term “die polishing” is still sometimes used to refer to such salvage efforts, causing interminable confusion among collectors.

Alternative scenario unlikely

Hardesty proposed a slightly more complex scenario to explain this unusual error. He suggests that a strongly misaligned obverse (hammer) die collided with the top of the collar and that this collision left the step and the recess. He then suggests that Mint workers tried to salvage the die by polishing the damaged area.

A scenario involving collar clash and a subsequent repair job seems unlikely to me. It makes no sense to a repair such a heavily damaged die. There are no recorded cases of collar clash this offset and this severe among circulation strikes. A die dent generated by such a collar clash is unlikely to produce such a sharp step. Finally, the outer margin of the obverse die face retained its convexity (leaving a bowl-shaped perimeter on the coin). A collision as severe as Hardesty proposes should have flattened out that convexity.

Since die errors are repetitive, it is possible that more of these 2009-S Northern Mariana Islands quarter dollars remain to be found.

Coin World’s Collectors’ Clearinghouse department does not accept coins or other items for examination without prior permission from News Editor William T. Gibbs. Materials sent to Clearinghouse without prior permission will be returned unexamined. Please address all Clearinghouse inquiries to cweditor@coinworld.com or to (800) 673-8311, Ext. 172.

http://www.coinworld.com/articles/crescentic-plateau-emerges-from-proof-polishi/

Copyright 2012 by Amos Hobby Publishing Inc. Reposted by permission from the March 22, 2012, issue of Coin World.)

Certain error coin production patterns often

mystifying.

By Mike Diamond. | April 30, 2011 10:00 a.m. 

Article first published in 2011-05-09, Expert Advice section of Coin World

This Lincoln 1966 cent was struck by a horizontally misaligned obverse (hammer) die. The coin was struck in-collar and the reverse face is perfectly centered.

Image by Mike Diamond

The 20th and 21st centuries are studded with numerous spikes (and drops) in the production of specific error types. These spikes affect numerous categories of die, planchet and striking errors. Some surges in striking errors are easily explained. The year 1966 produced numerous rotated die errors (mostly 90 degrees) among Jefferson 5-cent coins. The vast majority can be traced to a single malfunctioning press. This same year brought us a less easily explained rash of Lincoln cents struck by horizontally misaligned obverse (hammer) dies. The misalignments are unusually severe, and head off in several different directions (see photo of 1966 Lincoln cent).

Lining up a quartet such errors, I was unable to match up the patterns of die scratches. Each coin was clearly struck by a different die pair; how many different presses were involved cannot be ascertained. Equally puzzling is the failure to see a similar error pattern in other denominations struck in 1966. Except for some rare instances, coinage presses are not dedicated to a specific denomination. Once the production totals for one denomination have been satisfied, the dies, collar and feeder assembly are changed to accommodate a different denomination.

Error production patterns confined to a single denomination are actually quite common and can stretch over several years. In the July 12, 2010, “Clearinghouse” column, I reported on a nine-year run of Lincoln cents with faint, oddly positioned clash marks (see photo of 1996 cent here). The clashes all occurred when the hammer die was tilted and horizontally misaligned to a remarkable degree — up to 50 percent. They’re so different from ordinary clash marks that it seems likely the mishaps occurred during installation rather than during a press run. Restricted to the years 1992 to 2000, the current count is 19 die pairs. Again, it’s unclear why the same mishap failed to occur when these presses were switched to other denominations.

An error production pattern can even be confined to a single design sub-type. In the Jan. 3 “Collectors’ Clearinghouse,” I reported on research conducted by Robert “BJ” Neff on tilted die clashes found in 1960-D Lincoln, Small Date cents (and one 1960 Small Date cent). An example of the 1960-D cent is shown here.

A tilted die clash occurs when the hammer die makes direct contact with the anvil die at an angle, leaving a set of reciprocal clash marks at one pole on each die. Such clashes are quite rare — except in this sub-type. At the time of writing, 35 such clashes have been cataloged, with at least 15 waiting in the wings for cataloging.

While examining more than 5,000 Small Date cents from both the Philadelphia and Denver Mints, Neff noticed some other intriguing patterns. Not a single conventional die clash (which produce the familiar “Lincoln in jail” effect) was found. Many of the dies from both Mints were covered by heavy die scratches, regardless of whether clash marks were visible. Die scratches are the product of intentional die abrasion, performed to remove clash marks and other types of superficial damage.

Neff also detected a high frequency of “conflicting dies” (switch-outs). These examples show clash marks on only one face; the opposite die was replaced before the press was restarted. Neff thinks that the presses responsible for the tilted die clashes and other effects were plagued by a number of problems: 1) difficulty in maintaining a horizontally oriented hammer die face, 2) difficulty in maintaining the minimum die clearance necessary to prevent a clash in the case of a planchet misfeed, and 3) an abnormally high rate of complete planchet misfeeds.

Neff thinks it’s possible that a different kind of press was used, or that a standard press was modified for the production of these Small Date cents. Whatever the changes, they didn’t work out very well and the experiment was abandoned.

Neff’s scenario only works if we surmise that the novel press design was used strictly for the small date cents. It also raises the question of why the cent design was modified after the experimental presses were abandoned. Conjecture aside, his evidence at least calls into question the standard explanation for the switch to the Large Date sub-type — a propensity for die chips to develop in digits of the small date.

Further details of Neff’s investigations can be found at www.maddieclashes.com.

Coin World’s Collectors’ Clearinghouse department does not accept coins or other items for examination without prior permission from News Editor William T. Gibbs. Materials sent to Clearinghouse without prior permission will be returned unexamined. Please address all Clearinghouse inquiries tocweditor@coinworld.com or to (800) 673-8311,

http://www.coinworld.com/articles/certain-error-coin-production-patterns-often-/

Copyright 2012 by Amos Hobby Publishing Inc. Reposted by permission from the March 22, 2012, issue of Coin World.)