What Machines Are Used to Make Money?

The creation of physical currency involves specialized machinery and meticulous steps. While often unseen, understanding this manufacturing process reveals a complex interplay of engineering, artistry, and security.

How Currency is Produced

The manufacturing of physical currency involves distinct processes for banknotes and coins, each relying on specialized machinery and materials. Paper currency, known as Federal Reserve notes, is made from a durable blend of 75% cotton and 25% linen, embedded with small red and blue security fibers. This unique substrate is produced by a single manufacturer, Crane Currency, and its possession by anyone other than the official printing entity is illegal.

The printing process for banknotes begins with intricate design and engraving. Artists and engravers create detailed elements transferred to steel dies, which are etched to produce master printing plates. The first printing stage for most denominations, except for the one-dollar bill, is offset printing. Large machines apply background colors and intricate designs simultaneously to both sides of the currency sheets at speeds up to 10,000 sheets per hour.

Following offset printing, or as the initial step for one-dollar bills, is the intaglio printing process. This technique applies specialized ink to engraved metal plates, transferring it under immense pressure to the paper, creating the distinctive raised texture of U.S. currency. This raised ink texture is a security feature difficult for counterfeiters to replicate. After intaglio printing, the sheets dry for approximately 72 hours.

The final printing stage for banknotes involves letterpress printing, which adds serial numbers, the Treasury seal, and the Federal Reserve seal and identification numbers. These elements are printed in green or black ink, depending on the note’s value. Following all printing stages, the large sheets of currency undergo rigorous inspection using Offline Currency Inspection Systems (OCIS). These systems use cameras and specialized software to scan both sides of the bills, identifying any defects or errors. Bills that pass inspection are then cut into individual notes and bundled for distribution.

The production of coins follows a different, yet equally precise, multi-stage process. It begins with the creation of coin designs, which are then used to produce steel dies. These dies strike the coin’s image onto blank metal discs. The metal for coins, which varies by denomination, is sourced in large coils. The first mechanical step in coin production is blanking, where a blanking press punches out circular blanks from metal coils at rates of up to 14,000 blanks per minute.

These blanks then undergo annealing, a heating process that softens the metal for striking, followed by washing and drying. Next, the upsetting process creates a raised rim around the edge of the blank, which helps protect the coin’s design and facilitates stacking.

The primary mechanical step is striking, where the blanks, now called planchets, are fed into high-speed coining presses. These presses force the obverse and reverse dies together against the planchet with pressure, imprinting the detailed design on both sides. A collar around the planchet prevents the metal from expanding excessively during striking. After striking, coins are inspected, counted, weighed, and packaged for distribution.

The Agencies Responsible for Money Production

The physical production of United States currency is managed by two distinct federal entities under the Department of the Treasury. These agencies ensure the consistent supply and integrity of the nation’s money, each with a specific role in creating legal tender.

The Bureau of Engraving and Printing (BEP) is the sole producer of Federal Reserve notes, commonly known as paper currency. The BEP operates production facilities in Washington, D.C., and Fort Worth, Texas, where billions of dollars in banknotes are printed annually. The BEP also produces other security documents for the U.S. government.

The U.S. Mint is responsible for manufacturing all circulating coins for the United States. Its primary purpose is to produce coinage for trade and commerce. The U.S. Mint operates four active coin-producing facilities located in Philadelphia, Denver, San Francisco, and West Point. In addition to circulating coins, the Mint also produces bullion coins, commemorative coins, and national medals.

Ensuring Currency Authenticity

Maintaining public trust in the nation’s currency requires measures to prevent counterfeiting. Both banknotes and coins incorporate numerous security features that deter illicit reproduction and allow for authentication. These features are continuously updated.

Banknotes include several overt and covert security features. One prominent feature is the unique paper composition, a blend of cotton and linen with embedded red and blue fibers. This distinct paper is difficult to replicate. Watermarks, faint images matching the portrait on the bill, are visible when held to light on denominations of five dollars and higher. Security threads are embedded vertically within the paper of denominations five dollars and higher; these threads are visible when held to light and glow different colors under ultraviolet light, with microprinting of the denomination and “USA” along their length.

Color-shifting ink is another security element, found on denominations of ten dollars and higher. The numeral in the lower right corner, and on the hundred-dollar bill, the Bell in the Inkwell, change color from copper to green when the note is tilted. Microprinting, tiny text that appears in various locations on the currency, is another deterrent. For example, on the hundred-dollar bill, microscopic text can be found along Benjamin Franklin’s collar and other areas, which becomes illegible on low-quality counterfeits.

Raised printing, resulting from the intaglio process, gives genuine bills a tactile feel that is difficult for counterfeiters to mimic. The hundred-dollar note also features a three-dimensional security ribbon woven into the paper, containing images of bells and “100s” that move as the note is tilted.

Coins also have specific anti-counterfeiting measures. The use of unique metal alloys and multi-layered or “sandwiched” metal compositions makes it difficult to replicate their exact properties. Many coins feature reeded edges, or milled edges, which are small grooves around the perimeter. This traditional feature was originally designed to prevent “clipping,” where precious metal was shaved off the coin’s edge, and now serves as a visual and tactile security measure.

More modern anti-counterfeiting technologies for coins include subtle variations in the reed pattern, such as a missing reed or notch, which can change position with each year’s release. Additionally, some coins incorporate micro-engravings or latent images, which are only visible under specific conditions or angles. The U.S. Mint also employs an anti-counterfeiting laboratory to test and authenticate coins, including those from programs like the Mutilated Coin Redemption Program.