What metals and materials are used in US coins and banknotes?



United States dollar (USD / US $) is also referred to as US dollar or US dollar. It is the official currency of the United States of America and its overseas territories. A US dollar is divided into 100 smaller units called cents.

Here is a brief overview of the history of currency in the United States:

  • In 1781, Congress chartered the Bank of North America in Philadelphia as the first national bank. This was to support the financial operations of the nascent government.
  • In 1785, Congress adopted the dollar as the monetary unit of the United States.
  • In 1792, the Coinage Act of 1792 created the US Mint and established a federal monetary system with fixed denominations for coins, and specified the value of each coin in gold, silver, or copper.
  • In 1861, the federal government circulated the first paper money.

Another day another dollar … but how are they made? Credit: © 2013 Photos.com, a division of Getty Images. All rights reserved.

Requirements for a metal coin

The metals used to make the parts are specifically chosen for long term service. The parts have a purpose and special requirements depending on the conditions they will meet. The metal used must therefore exhibit excellent wear resistance and anti-corrosion properties. Therefore, coins are usually made using alloys of base metals.

Care should be taken to ensure that the value of the metal in a coin is greater than the face value. This would allow founders to melt the parts and resell them. To counter this problem, parts are now made from a combination of metals such as cupro-nickel. Cupro-nickel is silver in color with wear resistance and excellent striking properties, which are essential for the design of the part.

Metals used in coins

Coins available at the United States Mint are made from a variety of metals. Exotic metals such as silver and gold were used by the United States Mint to make coins. However, due to the increase in the price of these metals, they are now only used for the manufacture of bullion coins or collector coins. Other metals such as copper, nickel, and zinc are used to make ordinary coins. Initially, the pennies were made of copper. But during the war years, the penny was even made from steel mixed with zinc to conserve copper for making weapons and shell casings. Today all pennies are made primarily from copper plated zinc.

Silver colored coins should not be confused with silver. These silver-colored coins are quarter, nickel, and dime coins, made using a copper-nickel combination. In the past, only the faces of the coins were plated, which caused the coins to rust. However, advanced technology has eliminated these problems. Today, steel is added in the manufacture of all parts. Metal prices strongly control the metal used, although new technologies are available.

Materials used in United States banknotes

The Bureau of Engraving and Printing (BEP) develops and produces US banknotes. American banknotes or paper money are made of 75% cotton and 25% linen. This is what gives the currency of the United States its distinctive look and feel. The paper and ink used in the production of American paper money are as distinct as their design. The quality of the paper is very high because it would take almost 4,000 double folds (first forward and then back) before a note tears.

The BEP receives the paper in brown paper packets of 20,000 sheets, ie 2 pallets of 10,000 sheets. Each sheet is monitored by the BEP throughout the production process. The total 20,000 sheet inventory is constantly monitored to ensure each sheet is accounted for. The currency paper is specially designed for BEP by Crane Paper Company. For bills of $ 5 and over, a security thread and watermark are already integrated into the paper when it is received.

The approximate weight of a banknote, regardless of its denomination, is 1g. In 1929, small sized banknotes were introduced in green color, as a pigment of this color was readily available in large quantities. The color was also known to have high resistance to chemical and physical changes. Psychologically speaking, green was identified with the government’s strong and stable credit. Soon, these banknotes acquired the nickname “greenback”.

The design of the coin is updated with additional complexity from time to time to make counterfeiting more difficult. It has also been updated with features that will help the public to easily distinguish the denomination. These features have been designed with the needs of people with visual impairments in mind.

Specifications for Legal Tender Parts in the United States

The following table provides specifications for parts that are legal tender in the United States.

Denomination Metal used Composition (%) Weight (g) Diameter Thickness (mm) Edge Number of reeds
Hundred Copper plated zinc 2.5 Cu Balance Zn 2,500 0.750 in (19.05 mm) 1.55 Plain N / A
Nickel Cupro-Nickel 25 Ni Balance Cu 5,000 0.835 in (21.21 mm) 1.95 Plain N / A
Dime Cupro-Nickel 8.33 Ni Balance Cu 2,268 0.705 in (17.91 mm) 1.35 Reed 118
Quarter dollar Cupro-Nickel 8.33 Ni Balance Cu 5.670 0.955 in (24.26 mm) 1.75 Reed 119
Half a dollar Cupro-Nickel 8.33 Ni Balance Cu 11,340 1.205 in. (30.61 mm) 2.15 Reed 150
Presidential $ 1 Manganese-Brass 88.5 Cu 6 Zn 3.5 Mn 2Ni 8.1 1.043 in. (26.49 mm) 2.00 Border-lettering N / A
Native American $ 1 coin Manganese-Brass 88.5% Cu 6 Zn 3.5 Mn 2 Ni 8.1 1.043 in. (26.49 mm) 2.00 Border-lettering N / A

How are metal parts produced in the United States?

All American coins are minted by the United States Mint. The production of millions of metal parts a day is a complex process that requires people and machines to work together efficiently and in unison.

The six main stages in the making of American coins are shown below:

  • The first step is known as removal. Blanks are cut from coiled strips of metal measuring 13 inches by 1,500 feet in a die-cutter. The remaining strap is cut and recycled. The cent is the only coin stamped on prefabricated blanks.
  • The next step includes annealing, washing and drying the blanks. The blanks are heated in an annealing oven to soften them, then they are sent to a washer and dryer.
  • The third stage is called upsetting, where the good blanks are passed through a upsetting mill so as to raise a rim around their edges.
  • The fourth step is striking. The blanks are passed through a punching press. In the press, they are stamped with designs and inscriptions that give them the authentic appearance of United States coins.
  • The fifth step is the inspection during which press operators use magnifying glasses to check each batch of newly minted coins.
  • In the sixth and final step, the coins must be counted and bagged. This is done using an automatic counting machine that counts the coins and places them in large bags. Forklifts transport sealed bag pallets to vaults for storage. From there, the trucks take the new coins to the Federal Reserve banks and then to the local banks.



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