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Planchet

Planchet is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Planchet rather than just read about it. In short: A planchet English: is a round metal disk that is ready to be struck as a coin. An older word for planchet is flan.

Planchet — main illustration
Planchet — illustration

Key takeaways

  • Planchet belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Planchet to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Planchet from memory before moving on to harder problems.

Reference excerpt

A planchet English: is a round metal disk that is ready to be struck as a coin. An older word for planchet is flan. They are also referred to as blanks.

History The preparation of the flan or planchet has varied over the years. In ancient times, the flan was heated before striking because the metal that the coin dies were made of was not as hard as dies today, and the dies would have worn faster and broken sooner had the flan not been heated to a high temperature to soften it. An unusual method was used to mint the one-sided, bowl-shaped pfennigs of the Holy Roman Empire. The planchet used for these so-called Schüsselpfennigs was larger than the coin die itself. The coins were made by striking with only one upper die on the larger planchet. As a result, the perimeter of the planchet was pressed upwards in the shape of a bowl or plate. Until the 18th century they were minted mainly in the Harz Mountains. The curved shape of the pfennig was very useful for handling small change because it was easier to grip than a flat coin.

Modern striking Today's dies are made from hardened steel, and the presses use many thousands of pounds of force to strike coins (varying according to the size of the coin and the complexity and relief of the design). In addition, today's coins have much lower relief than ancient coins. Because of this, the planchet no longer needs to be heated immediately before striking, although it is annealed by heating and slow cooling which softens the coin.

Preparation

Preparation of the modern planchet involves several steps. First, the metal (or metals in the case of clad or multilayered coins) is rolled out into a large roll or sheet of the correct thickness. This process is often done by third parties, not by the mint itself. These flat rolls or sheets of metal are then punched out into round blanks that are a little larger than the coin being struck. The blanks are then subjected to an annealing process that softens the metal through heating to approximately 750 degrees Celsius (1400 degrees Fahrenheit) and are then slowly air cooled. They are then washed to remove residue from the annealing process and dried.

Completion

Finally, the planchet is struck. After striking, it becomes a coin and is no longer a planchet. Occasionally, a planchet will escape the mint without having been struck. This is a blank planchet error, and is usually worth a few dollars for modern coins. Occasionally, blank planchets can be rare and valuable, such is the case for Morgan Dollar blank planchets, although authentication and appraisal by a coin grading service is highly recommended for such pieces as they would be fairly easy to counterfeit.

See also

Coining (mint) Counterfeit Punch-marked coins Coining press

References

External links

How coins are minted – an extensive description of the minting process through the ages winsociety.org Circulating coins (flash required) Minting Process

Illustrations

Planchet: Planchets in a press feed system, on their way to the stamping press.
Planchets in a press feed system, on their way to the stamping press.
Planchet: A 6,000-pound coil is fed into a blanking press at the US Mint.
A 6,000-pound coil is fed into a blanking press at the US Mint.

Worked examples

Example 1 — a first encounter with Planchet

Start with the simplest possible case. Write down what Planchet claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Planchet before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Planchet ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Planchet

In research
Planchet appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Planchet in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Planchet is common in secondary-school and first-year university syllabi. It links to neighbouring topics Coins, Currency production, so understanding it makes those chapters shorter.
In everyday life
Look for Planchet outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Planchet in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Planchet means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Planchet out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Planchet in simple terms?

A planchet English: is a round metal disk that is ready to be struck as a coin. An older word for planchet is flan.

Why does Planchet matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Planchet?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Planchet.

Tags

  • Coins
  • Currency production

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