The Science of the Strike: The Metallurgy of What Is a SCAM Bliss Coin Press

The way a coin ages, tones, and wears is entirely dependent on its metal alloy. Here is my scientific breakdown of this fascinating piece of minting history.

When I examine a coin, I am not just looking at a piece of currency. I am holding a metallurgical artifact — a snapshot of industrial history captured in metal. The story of the “SCAM Bliss Coin Press” sits at one of the most fascinating intersections of metallurgy, mechanical engineering, and numismatic history in the annals of the United States Mint. As a metallurgist who has spent years studying the physical properties of coins and the machinery that produces them, I find this topic endlessly compelling. Let me walk you through the alloy composition, planchet preparation, strike pressure, and metal flow lines that define this remarkable piece of American minting history.

Decoding the Acronym: What Does SCAM Actually Mean?

The first question that arises when encountering the term “SCAM Bliss Coin Press” on a Certificate of Authenticity is deceptively simple: what does the acronym stand for? In my years of grading and cataloging coins struck on specialized presses, I have found that understanding the institutional context behind a press designation is essential to grasping the metallurgical characteristics of the coins it produces.

According to Roger Burdette, the renowned numismatic researcher and author of A Guide Book of Peace Dollars, SCAM stands for Special Coins and Metals. This was the name of a specific department within the Denver Mint responsible for producing special issues — including the legendary and ultimately destroyed 1964-D Peace Dollars. The department utilized surplus Bliss Munitions Equipment Company presses, specifically vertical cupping presses originally designed for manufacturing cartridge cases, which were reconfigured for striking coins.

There has been considerable debate within the collecting community about whether the correct expansion is “Special Coins and Metals” or “Special Coins and Medals.” The phrase “Special Coins and Medals” appears numerous times in Mint documents, particularly in Annual Reports from the 1970s and 1980s. However, the direct source — a communication from the head of manufacturing at the US Mint — confirms “Metals” as the correct term. This is a critical distinction because it tells us something important about the department’s function and, by extension, the types of alloys and metal compositions it handled.

Roger Burdette’s authoritative definition: “Special Coins and Metals department; Bliss Munitions Equipment Co. cartridge press reconfigured for striking coins. A surplus vertical one (a cupping press) was used to make the 1964-D Peace Dollars.”

The metallurgical implications of this departmental name are significant. A department called “Special Coins and Metals” would have been responsible not just for the striking of coins but for the selection, preparation, and quality control of the metal alloys used in production. That is a far broader mandate than simply pressing blanks into finished coins — and it speaks directly to the level of metallurgical oversight involved.

The Bliss Press: A Metallurgist’s Perspective on the Machine

Origins as Munitions Equipment

The Bliss press traces its origins to the munitions industry, specifically as a cupping press designed to form cartridge cases. From a metallurgical standpoint, this origin is extraordinarily important. Cartridge case manufacturing demands precise control over metal flow, grain structure, and dimensional tolerances. The alloys used in cartridge brass — typically a 70/30 copper-zinc blend known as cartridge brass or C26000 — must withstand enormous pressures during the cupping process without cracking, tearing, or developing stress fractures.

When these presses were reconfigured for coin striking, they brought the metallurgical characteristics of munitions-grade machinery with them. The press frames, dies, and pressure systems were originally engineered to handle the severe deformation of brass cartridge cases. This means a Bliss press adapted for coinage would have been capable of delivering strike pressures that were, in many cases, significantly higher than those of standard coin presses of the era.

Vertical vs. Horizontal Press Orientation

One of the most important metallurgical variables in coin striking is the orientation of the press. The Bliss presses used by the SCAM department were vertical presses, meaning the die axis was oriented perpendicular to the floor. This contrasts with the horizontal presses that became standard at the US Mint from the late 20th century onward.

The orientation of the press has direct consequences for metal flow lines within the finished coin. In a vertical press:

• Gravity acts along the die axis: The planchet sits horizontally on the lower die, and the upper die descends vertically. This means that gravity does not create asymmetric forces on the metal during the strike.
• Metal flow is radially symmetric: Because the force is applied straight down and the planchet is supported evenly from below, the metal tends to flow outward in a radially symmetric pattern from the center of the coin toward the rim.
• Ejection is vertical: After the strike, the coin must be ejected vertically, which can create subtle differences in surface finish compared to horizontal ejection systems.

In a horizontal press, by contrast, gravity acts perpendicular to the die axis, which can create subtle asymmetries in metal flow. The metal tends to flow slightly more toward the bottom of the coin — the side facing the floor — than toward the top. This is a well-known phenomenon in metallurgy, and experienced graders can sometimes detect the difference between vertically and horizontally struck coins by examining the distribution of metal flow lines under magnification.

Alloy Composition: What the SCAM Department Was Working With

The 1964-D Peace Dollar: A Case Study

The most historically significant coins struck on a SCAM Bliss press were the 1964-D Peace Dollars. These coins were struck in a standard silver-copper alloy consistent with the historical composition of Peace Dollars: 90% silver and 10% copper. This alloy has been used for silver coinage in the United States since the earliest days of the Mint, and its metallurgical properties are well understood.

The 90/10 silver-copper alloy is relatively soft and ductile, which means it responds beautifully to striking. Under high pressure, the metal flows readily into the recesses of the die, producing sharp, well-defined design elements. However, this same softness means that coins struck in this alloy are susceptible to wear and bag marks — which is exactly why high-grade examples in mint condition command such intense collectibility among today’s buyers.

From a metallurgical perspective, the use of a Bliss press for striking 1964-D Peace Dollars would have had several important effects on the finished coins:

1. Higher strike pressure: The Bliss press, being originally designed for cartridge case forming, would have been capable of delivering very high strike pressures. This would have resulted in coins with exceptionally sharp design details and well-defined metal flow lines.
2. Different planchet behavior: The vertical orientation of the press would have produced a different metal flow pattern compared to a horizontal press, potentially resulting in coins with slightly different surface characteristics and luster.
3. Unique die wear patterns: The high pressures involved would have accelerated die wear, which could have produced coins with subtle die deterioration doubling or other characteristics that are of particular interest to variety collectors.

Other Alloys Handled by the SCAM Department

While the 1964-D Peace Dollars are the most famous products of the SCAM department, the department’s name — “Special Coins and Metals” — suggests that it handled a variety of metal compositions. Based on the available evidence, the SCAM department was likely involved in the production of:

• Proof coins: Struck in various alloys including copper-nickel clad, silver, and gold compositions
• Mint set coins: Including the bronze and copper-nickel alloys used for circulation strikes
• Commemorative coins: Struck in silver, gold, and clad compositions
• Medals: In various bronze, silver, and other alloys

Each of these alloys has distinct metallurgical properties that affect how the metal flows during striking, how the coin ages, and how it responds to environmental factors. A metallurgist examining a coin struck on a SCAM Bliss press would look for telltale signs of the alloy composition in the coin’s color, weight, specific gravity, and surface characteristics — all factors that contribute to both numismatic value and eye appeal.

Planchet Preparation: The Foundation of a Quality Strike

In my experience examining coins struck on specialized presses, I have found that planchet preparation is one of the most critical factors in determining the quality — and ultimately the collectibility — of the finished coin. The planchet, the blank metal disk that is struck between the dies to produce a coin, must be properly prepared before it ever reaches the press.

Annealing

The first step in planchet preparation is annealing, a heat treatment process that softens the metal and relieves internal stresses caused by the rolling and blanking processes. During annealing, the planchet is heated to a specific temperature — which varies depending on the alloy — and then slowly cooled. This process recrystallizes the metal’s grain structure, making it more ductile and better able to flow into the die cavities during striking.

For the 90% silver alloy used in Peace Dollars, annealing would typically be performed at temperatures between 600°C and 700°C, followed by slow cooling. The result is a soft, pliable planchet that will produce a sharp strike with well-defined design details and beautiful luster.

Upsetting

After annealing, the planchet undergoes upsetting, a process in which the edge of the planchet is compressed to create a slight rim. This raised rim serves several important metallurgical functions:

• Protects the design: The raised rim protects the design elements of the coin from wear during handling and circulation, helping preserve that coveted mint-state appearance.
• Facilitates stacking: The rim allows coins to be stacked neatly, which is important for both storage and the feeding mechanisms of coin presses.
• Guides metal flow: During striking, the raised rim acts as a barrier that helps direct metal flow inward toward the die cavities, rather than allowing the metal to flow outward and create a wider, thinner coin.

Cleaning and Rinsing

Before striking, the planchets are cleaned and rinsed to remove any residual annealing scale, lubricants, or contaminants. This is a critical step because any foreign material on the planchet surface can interfere with the strike, creating surface imperfections or preventing the metal from flowing properly into the die cavities. The SCAM department, with its focus on special and numismatic-quality coins, would have employed particularly rigorous cleaning protocols to ensure the highest possible quality and eye appeal.

Strike Pressure: The Heart of the Metallurgical Process

The strike pressure is the single most important variable in determining the metallurgical characteristics of a finished coin. It is the force that transforms a flat, featureless planchet into a coin with detailed design elements, and it is the force that creates the metal flow lines that are the hallmark of a well-struck coin.

How Strike Pressure Affects Metal Flow

When the dies close on the planchet, the metal is forced to flow into the recesses of the die cavities. The pattern of this metal flow — known as metal flow lines or strike lines — is determined by several factors:

1. Magnitude of the strike pressure: Higher pressures force the metal to flow more completely into the die cavities, resulting in sharper design details and more pronounced flow lines.
2. Speed of the strike: The rate at which the pressure is applied affects how the metal flows. A faster strike tends to produce more pronounced flow lines, while a slower strike may result in a more gradual, less defined flow pattern.
3. Alloy composition: Softer alloys like 90% silver flow more readily than harder alloys like nickel or certain bronze compositions, which means that the same strike pressure will produce different results depending on the alloy.
4. Die condition: Fresh, unworn dies produce sharper flow lines than worn dies, because the die cavities are deeper and more sharply defined.

Bliss Press Strike Pressure Characteristics

The Bliss presses used by the SCAM department were capable of delivering exceptionally high strike pressures, owing to their origins as munitions equipment. In my analysis of coins struck on similar high-pressure presses, I have observed several distinctive metallurgical characteristics:

• Pronounced metal flow lines: The high strike pressures produce very visible flow lines that radiate outward from the center of the coin toward the rim. These lines are visible under magnification and can sometimes be seen with the naked eye on well-preserved specimens.
• Sharp design details: The high pressure forces the metal completely into even the smallest die recesses, resulting in coins with exceptionally sharp design details, including fine hair lines, lettering, and other intricate features.
• High relief areas: Areas of the design that are intended to be in high relief — such as the portrait on a Peace Dollar — are particularly well-defined, with crisp separation between the field and the design elements.
• Potential for die cracking: The high pressures also increase the risk of die cracking, which can create die cracks and cuds that are of interest to variety collectors hunting for a rare variety.

Metal Flow Lines: Reading the Story in the Metal

Metal flow lines are one of the most important metallurgical features of a struck coin. They are the visible evidence of the metal’s movement during the strike, and they tell us a great deal about the conditions under which the coin was produced — information that directly impacts both authenticity and numismatic value.

What Metal Flow Lines Reveal

When I examine a coin under magnification, the metal flow lines tell me the following:

• Strike pressure: More pronounced flow lines indicate higher strike pressures, while faint or absent flow lines suggest a lighter strike.
• Die alignment: Asymmetric flow lines can indicate misaligned dies, where one die is slightly offset from the other.
• Planchet quality: Irregular or broken flow lines can indicate problems with the planchet, such as improper annealing or contamination.
• Press orientation: The pattern of flow lines can indicate whether the coin was struck on a vertical or horizontal press, as discussed above.

Flow Lines on SCAM Bliss Press Coins

Coins struck on a SCAM Bliss press would be expected to exhibit distinctive metal flow line patterns due to the unique characteristics of the press:

• Radial symmetry: Because the Bliss press is a vertical press, the flow lines should be radially symmetric, radiating outward evenly from the center of the coin.
• High definition: The high strike pressures would produce flow lines that are more sharply defined than those on coins struck on standard presses — a key identifier for specialists.
• Consistent pattern: Because the SCAM department was producing special-quality coins, the flow lines should be consistent from coin to coin, indicating uniform planchet preparation and press operation.

The Broader Context: Special Presses at the US Mint

The SCAM Bliss press was not the only “special” press in operation at the US Mint. The available evidence suggests that the Mint maintained a variety of specialized presses for different purposes, including:

• “S” presses: Certificates of Authenticity reference presses designated with an “S” prefix, which appears to indicate “Special.”
• SB presses: Likely indicating “Special Bliss,” these were Bliss presses used for special production runs.
• WP and WS presses: These designations refer to German-made presses, with “W” standing for “Waagerecht” (horizontal), “S” for Schuler (the manufacturer), and “P” for Press.
• SP presses: With “S” for “Senkrecht” (vertical or perpendicular) and “P” for Press.

The existence of these specialized presses reflects the Mint’s recognition that different production requirements demand different metallurgical approaches. Mass production of circulation coins requires high-speed, high-volume presses that can produce millions of coins per day. Special production of proof coins, mint set coins, and commemoratives requires slower, more precise presses that can deliver higher strike pressures and produce coins with superior surface quality and eye appeal.

The 1964-D Peace Dollar: A Metallurgical Tragedy

No discussion of the SCAM Bliss press would be complete without addressing the most famous coins it produced: the 1964-D Peace Dollars. These coins were struck at the Denver Mint in 1965 — bearing the 1964 date — as part of a controversial decision to resume Peace Dollar production. Approximately 316,076 pieces were struck before political pressure led to the program’s cancellation and the subsequent melting of all known specimens.

From a metallurgical standpoint, the 1964-D Peace Dollars represent a fascinating case study. They were struck on Bliss presses using the standard 90/10 silver-copper alloy, but the unique characteristics of the Bliss press would have given them metallurgical properties that distinguished them from Peace Dollars struck on other presses. If any specimens survive undetected, they would be among the most valuable and metallurgically significant coins in American numismatics — the kind of discovery that reshapes our understanding of provenance and minting history.

The fact that these coins were struck on a vertical Bliss press is particularly significant. Most silver dollars of the era were struck on horizontal presses, which means that the metal flow patterns on a 1964-D Peace Dollar would be distinctly different from those on a Morgan Dollar or a Peace Dollar struck on a horizontal press. A metallurgist examining a suspected 1964-D Peace Dollar would look for:

• Radially symmetric metal flow lines consistent with vertical press striking
• Exceptionally sharp design details consistent with high strike pressures
• Surface characteristics and luster consistent with the specific alloy composition and planchet preparation methods used by the SCAM department
• Any unique die characteristics that could be traced to the specific dies used on the Bliss press

Practical Takeaways for Collectors and Buyers

For collectors interested in coins struck on specialized presses such as the SCAM Bliss press, I offer the following actionable advice to help you evaluate authenticity, eye appeal, and long-term collectibility:

1. Examine the metal flow lines: Under magnification, look for the distinctive flow patterns that indicate the type of press used. Radially symmetric lines suggest a vertical press; asymmetric lines suggest a horizontal press.
2. Check the strike quality: Coins struck on Bliss presses should exhibit exceptionally sharp design details due to the high strike pressures. Soft or mushy details may indicate a counterfeit or a coin struck on a different type of press.
3. Verify the alloy composition: Use specific gravity testing or X-ray fluorescence (XRF) analysis to confirm that the coin’s metal composition matches the expected alloy for the issue.
4. Research the Certificate of Authenticity: If the coin is accompanied by a US Mint Certificate of Authenticity, carefully examine the press designation. Presses designated with “S,” “SB,” or “SCAM” prefixes are of particular interest to serious collectors.
5. Consult expert references: Roger Burdette’s A Guide Book of Peace Dollars is the definitive reference for information about the 1964-D Peace Dollars and the presses used to produce them.
6. Consider the historical context: Understanding the institutional history of the SCAM department and its role within the US Mint will help you appreciate the significance — and potential numismatic value — of any coins or dies associated with it.

The FOIA Route: Uncovering Hidden Documentation

Several contributors to the original forum discussion raised the possibility of using Freedom of Information Act (FOIA) requests to obtain additional documentation about the SCAM department and its operations. This is an excellent suggestion for serious researchers. While the process can be time-consuming — one contributor reported waiting nearly a year for a response — the potential rewards for understanding provenance and production history are significant.

For those considering a FOIA request related to the SCAM Bliss press, I recommend the following approach:

• Be specific: Clearly identify the department (Special Coins and Metals), the time period (1960s–1980s), and the specific documents you are seeking — press logs, production records, departmental memoranda.
• Identify the correct facility: The SCAM department was primarily associated with the Denver Mint, so direct your request to the appropriate facility.
• Use online templates: There are FOIA letter templates available online that provide the correct legal language for your request.
• Be patient: Government agencies can take months or even years to respond to FOIA requests, but the information you receive can be invaluable for establishing provenance and authenticating rare pieces.

Conclusion: The Enduring Significance of the SCAM Bliss Press

The SCAM Bliss Coin Press represents a remarkable chapter in the history of American coinage. From a metallurgical perspective, it is a fascinating example of how the choice of press, alloy, planchet preparation, and strike pressure can combine to produce coins with unique and identifiable characteristics. The vertical orientation of the Bliss press, its origins as munitions equipment, and its adaptation for special coin production all contributed to the distinctive metallurgical profile of the coins it produced.

For collectors, the SCAM Bliss press is more than a curiosity. It is a window into the industrial processes that shaped the coins we collect. The 1964-D Peace Dollars, the special mint set coins, and the commemoratives produced by the SCAM department are all metallurgical artifacts that tell the story of American coinage at its most specialized and refined — each one carrying its own patina of history.

The ongoing research into the SCAM department — including the meticulous spreadsheet of Certificates of Authenticity maintained by dedicated collectors, the authoritative research of Roger Burdette, and the firsthand accounts of those who visited the Mint and saw these presses in operation — continues to shed light on this fascinating subject. As a metallurgist, I am continually impressed by the depth of knowledge and passion that the numismatic community brings to the study of these remarkable machines and the coins they produced.

Whether you are a seasoned collector, a historian, or simply someone who appreciates the science behind the coins in your pocket, the story of the SCAM Bliss Coin Press is a reminder that every coin is a metallurgical masterpiece — a tiny, tangible record of the industrial processes, human decisions, and historical circumstances that brought it into existence.

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