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    striking pressure

    From Mine To Mint

    /2013

    situation, the accidental introduction of two or more planchets at the same time increased the actual pressure tremendously. This capacity oversizing and robust construction allowed the press to withstand decades of high-energy operation without cracking or other structural damage. Very few toggle presses suffered structural failures.^* In 1896 striking pressure for gold coins was reported as: $20, 175 tons; $10, 120 tons; $5, 75 tons; and $2.50, 40 tons. In 1922 similar but slightly lower pressures were reported. These have always been assumed to be “tons per square inch.” A problem with these assumed values is that independent metallurgical and mint sources state that the maximum pressure that could be used on steel dies of this era was 150 tons per sq


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    From Mine To Mint

    /2013

    situation, the accidental introduction of two or more planchets at the same time increased the actual pressure tremendously. This capacity oversizing and robust construction allowed the press to withstand decades of high-energy operation without cracking or other structural damage. Very few toggle presses suffered structural failures.^* In 1896 striking pressure for gold coins was reported as: $20, 175 tons; $10, 120 tons; $5, 75 tons; and $2.50, 40 tons. In 1922 similar but slightly lower pressures were reported. These have always been assumed to be “tons per square inch.” A problem with these assumed values is that independent metallurgical and mint sources state that the maximum pressure that could be used on steel dies of this era was 150 tons per sq


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    John Reich Journal, July 2011

    7/1/2011

    erses A, B and C all failed with CUD’s and/ or extreme cracking. Obverse 1 finally failed with a CUD at Stars 8 and 9 (Scuderi, 2008). Having collected and studied this obverse extensively, I know of no 1830 JRl dime with perfect dentils. Even very early die state coins of this variety show dentil deterioration unlike any I have seen. I believe that this deterioration may be due to an increase in striking pressure designed to bring up the detail on a slightly wider rimmed coin. The result was a stronger strike on the periphery of the coin and a loss of some detail on the central devices. With the above in mind, I propose the following minting sequence to explain the 1829 JR 10 dime. In early 1830, Obverse 1 was married to Reverse A to produce 1830 JRl. Obverse 1, with its wider rim, was an experimental die


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    1838-O HALF DOLLAR RESEARCH

    10/30/2016

    is original run were intended for circulation rather than as proofs for the Mint Director. Second, the original run had to use the dollar press because the half dollar press was not ready for production. The reverse half dollar die was too short to be secured into the larger dollar press, and Rufus Tyler, the Chief Coiner, had to splice it into place. We can infer that Tyler would have used lower striking pressure on his "jury rigged" system in an attempt to reduce the risk of failure. All the other specimens have very strong, sharp, strikes that are stronger than even the PROOF 1838 half dollars made in Philadelphia. We can conclude that these other specimens COULD NOT HAVE BEEN MADE ON THE DOLLAR PRESS AT A LATER DATE because their strikes are too strong. 5) All other specimens are PROOFS


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    From Mine To Mint

    /2013

    a more or less standard 1.5 to 1 ratio of reed height to width was informally adopted by the engraver George Morgan. The opening at the top of the edge collar was very slightly wider than at the bottom. This reduced friction was the coin was ejected, and helped avoid brock- ages from incompletely ejected coins. The results were particularly important when striking large volumes of silver dollars. striking pressure All mint presses of this era held one pair of dies. Dual presses were not used until 1944 and did not enter into general production until about 1950. Striking pressure was reported in mint documents as tons per square inch. However, strict acceptance of this creates certain problems relating to the strength of die steel. It appears that pressure was measured as total force rather than as force di


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    From Mine To Mint

    /2013

    a more or less standard 1.5 to 1 ratio of reed height to width was informally adopted by the engraver George Morgan. The opening at the top of the edge collar was very slightly wider than at the bottom. This reduced friction was the coin was ejected, and helped avoid brock- ages from incompletely ejected coins. The results were particularly important when striking large volumes of silver dollars. striking pressure All mint presses of this era held one pair of dies. Dual presses were not used until 1944 and did not enter into general production until about 1950. Striking pressure was reported in mint documents as tons per square inch. However, strict acceptance of this creates certain problems relating to the strength of die steel. It appears that pressure was measured as total force rather than as force di


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    United States Proof Coins 1936-1942

    /2017

    Circulation and Proof Coin Specifications Of the specifications shown below, only the weight and diameter were part of the coinage laws. Other measurements were working dimensions use in the Coining Department. striking pressure and diameter of blanks and planchets were flexible to allow for manufacture of the best product the dies could produce. (Specifications for silver dollars are included for completeness. The last proof silver dollars were made in 1904.) One Cent Five Cents Dime Quarter Half Dollar Dollar Diameter of Blank 0.754 0.828 0.704 0.960 1.195 1.506 Thickness of Blank 0.049 0.064 0.038 0.051 0.066 0.089 Di


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    MORE ON COIN STRIKING PRESSURE CALCULATIONS

    MORE ON COIN STRIKING PRESSURE CALCULATIONS

    06/13/2010

    MORE ON COIN striking pressure CALCULATIONS http://www.coinbooks.org/esylum_v13n24a13.html Last week Dick Hanscom asked: So here is my physics problem. I have built a "new and improved" (read heavier) drop hammer. I am curious how many pounds per square inch will be created upon impact on my die. The weight is 50 Pounds. The distance is 5 feet. The surface area of the die is 1.25 square inches. Using the Internet I am able


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    N.O. W. News, August 1983

    8/1/1983

    the uncirculated coin,, using the ANA categories of' MS 70, 67, 65, 63, and 60,. His illustrated grade guide lists and defines the high points on both the obverse and reverse to assure the uncirculated start point, f IGUftt A I Cf€CK POINTS FOA SIGNS OF WCAR (RU0BINGI TO DOtRMINC If SPFCIMCN IS UNCIRCULATED A second quality defini- tion is then added, "strike quality". This describes any improper striking pressure,, worn or weak dies, or plan- chet defects. Three catagor— ies are used, full, medium,, and weak strike quality. The final criteria, the steps on Monticello have been micro examined and the number unbroken and complete give the degree of perfec- tion of the coin. ^ TREAD RISER 7BEAQ J RISER STEP I STEP 2 FIGURE 0 Uhen viewed head on, as are the steps leading up to Monticello on tl ' reverse of a


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    Coinage Of The American Confederation Period (COAC #11)

    /1996

    equent annealing, cracks, delaminations, and shallow strikes result and inferior coins are produced. We now consider the hypothesis that counterfeiters used inferior production equipment and naive technologies as compared to the equipment and technologies used by the Royal Mint. These technologies might include, but are not limited to, inferior coin presses resulting in reduced and irreproducible striking pressure and improper annealing procedures during rolling, blanking, and before striking. To test this hypothesis let us consider two pairs of correla- tion plots. Fig. 5 shows a correlation plot of the weight of each coin in The Study Collection against its corresponding vertical diameter, i.e., its size. We see, not surprisingly, a strong correlation between weight and size. The interesting feature in t


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    E-Gobrecht, vol. 5, no. 12

    12/1/2009

    when the date and mintmark are in very similar positions on different dies. Distinguishing die characteristics such as scratches and cracks can help to differentiate different dies with similar date or mintmark positions. One must be very careful with these types of die markers, though, as cracks, scratches, and even small differences in position can change during die usage due to factors such as striking pressure, die wear, die polishing or re- work, and grade of the coin. It is not surprising that coins struck from different dies can appear quite simi- lar. It is less obvious just how frequently coins struck from the same dies appear quite different due to the factors mentioned. The purpose of this note is to dem- onstrate the progression of two specific die characteris- tics with die state for the 1844-


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    E-Gobrecht, vol. 9, no. 10

    10/1/2013

    ppealing most often note that it is hard to attribute and “not a naked eye variety.” Personally, I tend to think of the 1857 with Flying Eagle Cent clash is a misunderstood variety. First, like any coin issue, not all examples are creat- ed equal. But, in addition to strike, technical grade, surfaces, luster and eye appeal, the strength of the clash also varies between examples. Apparently due to striking pressure, and/or die wear after the clash, even coins with similar strike characteristics and grade can have clash marks with notably different definition. Examples in lower grade (VF and be- low), with weak clash marks, or with too much em- bedded dirt and crust can be quite difficult to attrib- ute. Examples in high grade, with strong clash marks, or with clean surfaces are attributable with the naked e


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    The Colonial Newsletter, no. 42

    12/1/1974

    December 1974 THE COLONIAL NEWSLETTER SequenHal page 467 SPECIMEN #4 Reverse Order Brockage MOS 30-hh.l of 1787 MOS Type C First strike — Planchet centered on reverse die, fully struck coin offset 50% produced reverse brockage. striking pressure appears to hove been relatively light. Second strike — Reverse remained centered on die os during first strike, and both obverse and reverse received full striking force. This specimen is very si miliar to specimen ^3 in that the first strike was offset and the second was the normal well centered strike, and - further - the elements of lettering in the central area were not obliterated for the sa


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    The Colonial Newsletter, no. 63

    7/1/1982

    lly British tokens of the era and the Nova's, as well as New Jersey cents and half cents, Vermont coppers, and the New York issues. Near mint state condition is needed to be certain that edge damage effects are minimal. We request that our Patrons having such specimens examine their specimens and advise us of their findings. 12. It is generally believed that the rounded edge effect is a result of striking pressure; however, examination of specimens struck well off center indicate that this is not the case. 13. Forensic scientists identify bullets fired from a gun by comparing markings on the bullets produced during travel down the gun barrel. Similiar markings are produced on the edges of planchets cut on a telescoping planchet cotter and it is relatively easy to compare planchets and identify coins that o


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    The Colonial Newsletter, no. 75

    3/1/1987

    se die cud above the bust of George III. Later, in 1789, when obverse 9 was used again, this time to strike variety 9-87NY, it was intentionally set in the coinage press so that the broken part of the die tilted away from the face of the reverse die (non-parallel dies). This was probably done in an effort to obtain greater life from the die by relieving the broken part of the die from some of the striking pressure. As a result, variety 9-87NY is virtually non-struck near the top of the obverse and on the opposite area of the reverse. ACKNOWLEDGMENTS The author is indebted to Walter Breen for sharing his observation that the 1771 through 1776 (large date only) dated American-made British halfpence were made from some of Walter Mould's letter punches. Also, the hypothesis that James Atlee obtained Mould's no


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    The Colonial Newsletter, no. 87

    1/1/1991

    was said to have been the first to cast type in America, the face appearing late 1766 in the printed works of Mein & Fleming, Boston printers. However, the same face is found in a London imprint of 1767 (J. Kirkpatrick’s translation of Tissofs Avis au peuple). Since it is contrary to the usual flow of commerce at that This paper has focused upon the Broken A punch because of its distinctiveness. striking pressure, direction of strike (i.e., dies can be in the same, or slightly different, horizontal plane), planchet quality, all can affect the appearance of punches on struck coins. Other punches traditionally ascribed to Atlee are not as distinctive as the Broken A. Photo-optical techniques are the surest methods for identifying punch links, given the diverse factors that can affect their shapes. 75 See Ap


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    The Colonial Newsletter, no. 93

    2/1/1993

    y have punched one character into the die at a different angle than the other. When a character is not punched perpendicularly into a die, the width of the character strokes can vary (either increase or decrease) along their length. Also, the engraver may have touched up the character by hand on one die and not the other. Another important factor is that collars were not used with the dies. Thus, striking pressure and the softness of the copper blank determines the amount of radial expansion during striking and how well the metal flowed into the character on the die. Die and coin wear will also change the appearance of the character. Therefore, the early American coinage researcher must expect to see variations (usually minor) between characters on coppers that were struck from dies prepared with the same


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    The Colonial Newsletter, no. 94

    7/1/1993

    y have punched one character into the die at a different angle than the other. When a character is not punched perpendicularly into a die, the width of the character strokes can vary (either increase or decrease) along their length. Also, the engraver may have touched up the character by hand on one die and not the other. Another important factor is that collars were not used with the dies. Thus, striking pressure and the softness of the copper blank determines the amount of radial expansion during striking and how well the metal flowed into the character on the die. Die and coin wear will also change the appearance of the character. Therefore, the early American coinage researcher must expect to see variations (usually minor) between characters on coppers that were struck from dies prepared with the same


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    The Colonial Newsletter, no. 118

    12/1/2001

    istence of S.1/1 and S.1/2 proofs, and their rarity. The two uncirculated business strikes and complete lack of circulated specimens support this theory. Given that both are struck from very early die states, it may well be that the uncirculated business strikes were trial strikes; made to ensure that all moving parts of the press were in alignment. Such strikes wouldn’t have been made under full striking pressure, norwould they have been done with specially prepared flans. At least one of these two known specimens exhibits proof-like fields, but is a soft strike. Thus, it is possible the dies were polished in anticipation of producing proof specimens. Under magnification, this specimen is softly struck; the letters are soft and rounded rather than sharp-edged as they are on proofs. A potentially contraven


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    The Colonial Newsletter, no. 145

    4/1/2011

    ommon matrix may have subtle differences. Different sets of punches produced by the same artisan may often exhibit a similar characteristic style. Punches that are light- ly impressed into a die will produce a slightly smaller character than that produced by the same punch that is strongly impressed. The angle and depth at which a punch is impressed into a die can also be a factor, along with the striking pressure of the die and the hardness of the planchet. Much the same can be said of central device punches. The same obverse bust device found on two different specimens and in combination with like punch linkage would almost certainly clinch the link. If two different device punches are used, they still may exhibit a similar characteristic design style. It was not uncommon for the engraver to hand strengt


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    The Colonial Newsletter, no. 148

    4/1/2012

    April 2012 THE COLONIAL NEWSLETTER Sequential page 3863 Figure 5. Obverse comparison of the Ringo-Martin (left) and Rock (right) "Banana Nose" varieties. the upright of an R. There is clear evidence of striking weakness at the viewer’s left on both known specimens, which suggests that the missing legend there is due more to misaligned dies or to problems with striking pressure. The new specimen is in a later die state than the discovery coin, showing die failure before the face, as well as some light breaks and swelling behind the head where the discovery coin shows a crude representation of ribbons. It was originally thought that this was overstruck (or possibly slightly double struck), but a closer ex- amination suggests that it is die failure. The reverse of the Rin


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    Gobrecht Journal #60

    7/15/1994

    , Reverse 4 die pair^. It is known that new polished dies can impart a prooflike surface onto coins for roughly the first 2500 strikes^. However, the first 500 or so examples would be expected to have significantly deeper reflective surfaces than those made toward the end of a 2500 piece run. The deterioration of prooflike qualities is a grudual event, as the dies start to wear from friction and striking pressure. As the dies lose their polished surfaces, the coins may tend to become more frosty or textured in appearance and some other types of die wear are usually in evidence. We know from Randy Wiley's article on the production of silver coins at the Carson City mint*, that 1 870-CC dollars were struck in February of 1 870 as follows: Date Quantity February 1 0th 2303 February 24th 1444 Total 3747 17


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    Gobrecht Journal #81

    7/15/2001

    ike created a bend in the coin at the collar, and the bend is still very slightly evident even after the second blow on top of it. This iDend indicates that the obverse was the hammer die, the known die orientation for half dimes during the striking process. Most of the details from the original strike remained visible only on the rims of the coin after the final strike. This occurred because the striking pressure was the lowest on the rims, the distance between the two dies being the 15


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    Gobrecht Journal #81

    7/15/2001

    within the collar. It is known that this procedure was followed for silver coins as well. In the case of the 1 838 half dime described in this article, it appears that the error was immediately discovered by one of the pressmen. The piece was salvaged by striking it again, this time on center and within the collar. The initial off center image was all but obliterated except on the rims where the striking pressure was the least. Steam power was introduced at the mint in 1 836 but this coin suggests that some of the early Seated coins were struck on the old screw presses. The new steam presses could produce coins at a much higher rate with less manpower. This new technology would eliminate the practice of salvaging error coins by striking them again within the collar. Obverse of Double Struck 1838 Half Dime


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    Penny-Wise, Vol. 44, No. 6

    11/1/2010

    paid employees at 830 per day, spent June 13* rolling copper with the higher paid Flude. He then spent June 18*, 19* and 20* cutting cent blanks, apparently all of those that would be used for SI lb and c and the Liberty Caps. Blanking, like edge milling, must have been a lowly job. Liberty Caps are nominally wider than Wreaths, but there is much overlap, and the difference may be due to greater striking pressure or the different characteristics of the dies. The “open collar” in which these coins were struck meant “no collar"^.” Of the jobs done by Schreiner (paid $124.48 for his work during the period), Sinderling (paid $1 14.10 for his efforts) and Guyer, we have no record. Casting, rolling, drawing, cutting, milling, annealing, cleaning and even boiling copper are easy to understand, but some jobs are


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    Penny-Wise, Vol. 46, No. 3

    7/1/2012

    e 1797 large cent illustrated on the previous page, are quite rare, but they generally command no premium, and many collectors prefer to pay less for such coins. The variety shown below shows the most extensive cud development found on any early copper. Some collectors try to obtain as many die states of this variety as they can. Because the early coppers were struck by hand on a screw press, the striking pressure was not always consistent, and some coins were weakly struck. Additionally, buckled or misaligned dies sometimes resulted in coins that are weakly struck in part, like the 1797 large cent on the previous page. In general, these variations add to the charm of early copper. They do not affect the coin’s grade, but they often affect collector demand for it and therefore its price, again because most


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    The MCA Advisory, December 2009

    12/1/2009

    ions should not be ignored. The medal must be struck or cast — each production method has its own challenges. For a struck medal, for example, it becomes easier to strike if the center represents its highest point. Metal fills that area better as striking force spread from the center to the edges of the piece. Also consideration needs to be given to how the front will fit to the back when tons of striking pressure is applied. 14. Lastly, (unless you want boxes of unsold medals in your cellar) your audience for the medal must be considered. (This may get into Alex Shagin’s category of the “psychology of perception” or whether a group assents to the medal lie issue by actually wanting to buy it.) Beyond its historical character, is the medal a piece you would want to display in your coin room? Design is fine


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    Journal of the Barber Coin Collectors' Society, vol. 12, no. 3

    9/1/2001

    lves seem to have the fewest. The dime reverse also has the most diverse variety,... The life of a die varies with the metal and size of the coin it is to strike. All the dies (during the Barber era) were made at the Philadelphia Mint,... The working dies are put to work in the striking presses which generate great pressure on the dies, often approaching 80 tons for the Bar- ber Dime issues. This striking pressure takes its toll on the hard- ened steel die, causing cracks to appear.” The above photos show BCCS member #266, Ralph Vignola’s 1914-D dime with a crack through the date, one through AMERICA and a filled R. On the reverse, there is a crack through the corn. Here we see the die crack in the rib- bon on the reverse of Ralph Vignola’s 1898 dime. As Russell Easterbrooks pointed out in his article, suc


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    Armenian Numismatic Journal, Series 1, Vol. 25, No. 1-4, and Bulletin No. 19B

    1/1/1999

    e of the coining die. The facts that the flaws are raised above the surface of the field and, when present, are repeated in the same pattern on each coin of its type, indicate that they are imparted to the coin from the dies, and not the result of damage to the coins after striking. These flaws can be visualized by a lOx magnifier, although in some cases they may appear faint due to variations in striking pressure. Careful examination of 42 well-preserved uncirculated examples of the cupronickel chess commemorative indicates that at least two pairs of obverse and reverse dies were used to strike this issue. The coins were classified into two varieties or types, described below, according to their specific die characteristics: Ty pe I Obverse: No noticeable imperfection. Reverse: A very short raised mark ap


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    The Shekel, vol. 2, no. 1 (Spring 1969)

    /1969

    of the tough ones to identify. The differences are mi- nute and the best way to anchor these differences is to physically examine both the proof and the regular issues together. There is a grain to the cupronickel plan- chets that is finer on the proofs. 1 have no knowledge of whether this exists because of finer finish- ing of the planchets for the proofs i.e. polishing, die polishing, great- er striking pressure or any com- bination thereof. The field (the blank spaces) has a higher lus- ter with less grain than the regular issue. The edge is sharper (not sharp or wire) than the regular and the letters and the insignia are more definitive. Beware of pur- chasing a polished regular piece as a proof. Look for the same lus- ter to exist in the field between the candles of the Menorah, the open- ings of the


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    The Shekel, vol. 5, no. 1 (Spring 1972)

    /1972

    are semi-frosted. Some of the BU coins have polished emblems and legends which do not differ from high reflective fields of the coins. Are these differences definite varieties? H, L., N. Y, C. A. Definitely not. The first strikes of a coin are ‘‘frosty” on the raised portions. Some first-strike BU coins have a better appearance than a late- strike proof. Because of the polished planchets, greater striking pressure and polished dies, the ideal coin is an early- strike “frosty” proof, Q. I received my LMPG BU and uncirculated coins from AINA. One of them must be an error. On the lapel pins, the lettering of the BU is cut into the pin while the one from the proof coin is raised. Which is the error? T, Richmond, Va. A. Neither. The lapel pins of the BU coins are incused and the lettering on the lapel pins whic


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    Gobrecht Journal #84

    7/15/2002

    exhibiting this phenomenon were all struck during the same general period at the mint and subject to the same mint conditions. One possible explanation might be that they were all produced at the second Philadelphia mint after the move to this new facility in 1 833. The steam press was used to strike the larger coins at this time but not the smaller coins like the half dime. Perhaps the increased striking pressure afforded by the steam press was sufficient to create die crumbling in the larger dies but the lower pressure from the screw press did not normally cause such die failures on half dime dies. Using the diagnostics gleaned from the many examples of the 1 838 V-1 0 half dime that I owned, I sought to locate a perfect die state example of the V-1 0 marriage. My search was rewarded with an EF-40 coin i


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    The TNA News, May-June 2014

    5/1/2014

    he process of making a proof coin, compared with business strikes ? 7) What is a planchet lamination, and how can I tell it from a die break? 8) What U.S. coin was produced on the thickest planchets? Hint: recent. Dr. Coyne 6) Proof coins are struck multiple times (usually twice in modern production) on specially prepared planchets from polished dies on presses which run slower and apply a higher striking pressure than those used to make business strikes. This makes possible the extra detail, mirror surfaces, and high square rims which we associate with modern proofs. 7) This is an example of a Lincoln Cent with a planchet lamination. A lamination is a type of error usually resulting from improper mixing of the alloy or contaminants in the alloy before it is rolled into coinage strip. After the coin is str


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    Penny-Wise, Vol. 10, No. 6(57)

    11/15/1976

    DIE STATE ANALYSIS Milton B . Pfeffer Around the time when political philosophers in the United States asserted that all men were created equal, all U.S. coins were being created unequal. The screw presses of the day accounted for this, inasmuch as striking pressures were inexactly and randomly applied , thus producing coins which were not of uniform sharpness . Because the striking pressure was a variable factor, it is necessary therefore, in examining the coins of that era today, to make allowances for the presumed variation from the standard, before one can intelligently judge or hope to recognize the state of the dies exhibited by any particular variety.


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    From Mine To Mint

    /2013

    rest, the bottom face of the collar descended just below the top of the die and closed the coining chamber. Simultaneously, the upper coin face die moved downward so that when the two face dies came closest together, the planchet metal was pressed into the coin designs of both face dies and the edge die.^® Gold and other coinage alloys were much softer and pliable than hardened die steel, and the striking pressure caused planchet metal to flow into the detail of the dies. This created the inverse of the die image, and also work hardened the planchet so that the resulting coin was much harder than the planchet and able to withstand years of circulation. The moment after striking, the upper die withdrew and moved upward. The collar moved downward until the feeders could push the coin to the discharge chute.


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    From Mine To Mint

    /2013

    ing or use of the drawbench. Drawbench marks could result from one of the rotating polished dies becoming stuck, or contami- nation of the strip lubricants. Any marks produced by debris on the rolls or drawbench dies, would have been too small to affect the weight of blanks. Cer- tain high-point lines on Morgan silver dollars can be attributed to this cause when a combination of design relief and striking pressure did not obliterate all of the fine scratches. Figure 135. Examples of silver strip scratches that were not pressed out of the planchet on striking. At left, very fine strip scratches run across Liberty 's cheek, lower ear and hair. At right, somewhat coarser scratches run diagonally across Liberty’s jaw, and deeper parallel marks are visible above her ear. The coins are both I880/79-CC silver dol


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    From Mine To Mint

    /2013

    trolled by rotation of the flywheel - faster rotation meant more cycles of the press per minute. Mechanically, the toggle-press delivered the same force with every actuation of the device, so striking pressure was largely a matter of die area and spacing. Thus, the number of cycles per minute was not directly related to the pressure of each strike. Coinage Presses - Philadelphia Mint, 1903 The mint had twenty-four coinage presses all of which were equipped with grav- ity feeds for the planchets. The planchets were placed in a basin on a tall stand at the front of the presses and the press operator (usu


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    Penny-Wise, Vol. 24, No. 3(138)

    5/15/1990

    in with superb detail, including even the faintest die cracks. Faint cracks on an early state can seem to disappear from an obviously later state that has seen some un- kind circulation. For these reasons, I try to avoid "states" that consist of a particular crack becoming thicker or heavier. Choice, well-struck examples do not predominate. Just as modern presses do not maintain constant tonnage, striking pressure from the screw press of the early 1800s was not uniform. The variance between start and end of shift, especially if lunch included a taste of the infamous demon rum, should show up on the struck coin. Also, while most coins are well centered, vertical die alignment in the press may have been off slightly. Most coins show weakness at the bow and the leaves to either side. (A few high grade example


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    The Colonial Newsletter, no. 95

    10/1/1993

    use split serifs, instead they used straight serifs. But the cleft can occur during striking, due to a phenomenon know as bifurcatio n. Many 1 8th century coppers were struck without retaining collars. Therefore, when the dies impacted the planchet during striking, it was possible that a considerable outward flow of metal could occur from the planchet center. The amount of flow was dependent upon striking pressure and planchet hardness. The impression near the edge of the planchet could be carried outward by this metal flow. If the metal flow was great enough, it split the bottom horizontal serifs of the legend letters, carrying each side of the serif outward and creating a cleft foot. Thus, Dale’sobservation provides additional support to the theory that the “Blank Planchet” started life as a copper coin.


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    Penny-Wise, Vol. 28, No. 5(164)

    9/15/1994

    Class III (predominant overstruck large size planchets) -- then. Class I (non- overstruck small size planchets) -- and finally. Class II (overstruck/non-overstruck medium size planchets); * An examination of the two very large (31 mm) Maris 17-b's is given which discounts these as errors resulting from a broken collar during the screw press operation. This then resulted in metal flow at K-3 from striking pressure producing a metal bulge at this location. Nevertheless, many planchets exists in Class III which are perfectly round, but not at this upper end in size diameter (31.0 mm). Background Problems continued at the Rahway Mint (first N.J. coppers minting operation after about a year of production, and on June 7, 1788, the equipment was placed by court order in the custody of the bondsman, Mathias Ogden


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    The Brasher Bulletin

    9/1/2006

    llowing the conclusion of the ceremony, guests were taken on a tour of the modern striking facilities at the third San Francisco Mint which are generally not open to the public. Proof silver dollars were being manufactured at the time. The production presses were striking the blanks with six blows of 1 60 tons per square inch each. Apparently, the ceremonial press had been adjusted with a greater striking pressure to allow only three blows. The gold coins had been struck a few weeks earlier with a full run to fill existing orders. This was the first time since 1984 that gold coins had been made in San Francisco. Flence, extra security precautions had to be added at the time because of the amount of precious metal on site. The tour also showed the automated packaging assembly lines as well as die polishing


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    American Numismatic Association Certification Services, 1983

    1/1/1983

    res of the die break on the 1861 "0" Mint Ealf Dollar. The extra breaks do not seem to be on either example I have, but both of them are worn. I think we ought to check the American Numismatic Society example of the Confederate Half Dollar unless you have already done this to deter- mine whether the new breaks exist on it. It ha 9 occurred to me that breaks may be weaker or may not show up if the striking pressure Is not as great. In other words, if a planchet is a little thinner or is hot, the die break should not show up as well. If a planchet were too thick the die break might be more evident. Does this make any sense? Thanks for developing the problem. Sincerely, Eric P. Newman Jah


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    Maryland TAMS Journal, Vol. 12, No. 3 (49)

    9/1/1991

    er the English stopped. The English started in the 1600 's while the Americans began just before the start of the Civil War. Of particular interest to the reviewer was the section on the various p techniques used to engrave love tokens. One variety was pinpunching. A sharp instrument was used to punch numerous indentations to a similar depth in the I area that was to be delineated. Differences in striking pressure often caused irregularities in the finished product when compared to hand engraving. The .land engraving section detailes the various methods and tools used to develop the finished product. The work is in the 8 1/2 by 11 inch format, printed on high quality paper fith card covers. Copies are available directly from the author at a price of $45.00 + $3.00 for postage and handling. Contact Mr. L. L


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    American Numismatic Association Numismatic Terms Standardization Committee Correspondence and Ephemera, 1966

    /1966

    e-coin can best be used here. PROOF PROOF This is a procedure of die-making and preparation of blanks followed by stamp- ing in a special way with special equipment. It is not a grade or condition, but a method of manufacture.- R. S. Yeoman * 3 “ " ' a SURFACE A- u* MW *J v S M The mirror-like finish imparted on specially produced coin, by the using of polished planchets and polished dies, higher striking pressure and double striking. MINT LUSTER A brightness imparted on the surface of a coin by the striking die during the process of manufacture. This sheen disappears soon after the coin is placed in circulation and is handled. Krause Publications, lola, Wis.


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    American Numismatic Association Numismatic Terms Standardization Committee Correspondence and Ephemera, 1966

    /1966

    misnomer. The accepted Fleur-de-coin can best be used here. PROOF This is a procedure of die-making and preparation of blanks followed by stamp ing in a special way with special equipment. It is not a grade or condition, but a method of manufacture.- R. S. Yeoman PROOF SURFACE The mirror-like finish imparted on specially produced coin, by the using of polished planchets and polished dies, higher striking pressure and double striking. MINT LUSTER A brightness imparted on the surface of a coin by the striking die during the process of manufacture. This sheen disappears soon after the coin is placed in circulation and is handled. Krause Publications, lola, Wis.


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    American Numismatic Association Numismatic Terms Standardization Committee Correspondence and Ephemera, 1969

    /1969

    -w- WIRE EDGE, Slight flange on coins caused by excess striking pressure, generally characteristic of Proof coins (also KNIFE BDGB) and Proof Medals, but can appear on any struck coins from the given cause. WARNTCKS. Nickname for Wartime silver nickels. WORKING DIE. Die with incuse design (usually) used to strike coins directly; receives MM punch at Philadelphia. WORKING HUB (HOB). Hub with relief design (usually) from which many working dies are made. / -Y- YEDA SEN.


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    TAMS Journal, Vol. 41, No. 3

    6/1/2001

    However, weak strikes may sometimes give the appearance of normal wear. The brass ones often exhibit darkness in "splotched" areas, perhaps due to artificial aging with a chemical or due to the condition of the stock from which they were made. The aluminum ones often exhi- bit a "grainy" or darkened, gray surface. Often there is luster around the letters on dark aluminum pieces, pro- bably due to striking pressure causing metal flow. Some of each metal appear in "bright uncirculated" condition. It is difficult to say whether this resulted from the pressure setting of the press or from the condition of the raw material. 3. There is usually some sort of damage around the edges that I attribute to the method of pressing them, rather than striking them within a collar as would have been done by the Salt Lake S


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    E-Gobrecht, December 2016 (vol. 12, no. 12, whole no. 143)

    11/30/2016

    heavier planch- et, which would hopefully now meet acceptable weight tolerances. No doubt the blanks cut would retained at least some of the concave/ convex feature, and perhaps if a blank planchet was laid concave side down, the blank planchet would maybe rock back and forth on one axis. It would seem Ukely though, that such con- cave/convex features would not withstand the coining press immense striking pressure, but maybe in some small way contributes to the quality of strike seen in the resultant coin. justors during the day. The work of ''adjusting” is performed by fe- males of whom from ten to fifteen are employed, ac- cording to the amount of labor to be accomplished. An 1857 article gives the number of officers and employees at the Branch Mint at 95. The officers of the Mint were the Superintendent


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    Gobrecht Journal #90

    7/15/2004

    age. Cuds are frequently seen on 1 853 dimes and quarters that were struck in very large numbers. Interestingly, 1853 half dollars are much tougher to find with cuds. 3. It is possible that the new designs of 1853 required a change in metallurgical die processing that made the dies more prone to failure. The new design itself may have created more stress on the dies due to different metal flow or striking pressures. A study of cuds can document the deterioration of the coinage dies and show where the striking pressure was the strongest. Die cracks and cuds will also identify the weakest areas in the design where die damage is most likely to be found. ♦ Book Report: The Mint on Carson Street The Mint on Carson Street is a new book by Rusty Goe that describes the historical environment surrounding the constr


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    A Study Guide for "Fundamentals of Rare Coin Collecting and Investing" Home Study Course

    1/1/1981

    . A multiple die holder or fixture has two holes for the dies that have to be maintained on center between the obverse and re- verse dies. To check the die centering, the die setter places paper between the dies and it is pressed just enough to imprint it. The paper is then taken out and examined to see how well centered the dies are. Test strikes are also made by the die setter to set the proper striking pressure. These test coins are set aside to be remelted. The most critical thing used in the coining process are the dies . They are stored in a locked die and collar vault. They must be checked out by the die setter who signs for them on a record card. When the dies have worn out, they are destroyed by the mint. Four people must witness the destruction of unusable dies and three of these have to be from


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