United States Mint: Implementation of precision laser technology to engravetooling for over 30,000 work dies per year.

United States of America

The United States Mint’s nomination for Best New Coin Product, Process or Manufacturing Innovation is the implementation of precision laser ablation technology to engrave tooling for circulating coinage and work dies for small-run numismatic programs.

The Mint identified priority areas for implementing laser engraving into the traditional hubbing process that maximizes the investment of two lasers to produce over 30,000 work dies per year. Due to throughput limitations, the highest value for the Mint was identified as laser engraving tooling for circulation, bullion, and large-volume numismatic products. Direct laser engraved work dies are produced for short-run numismatic products. The decision to have coining quantities dictate production methods ensures that the benefit of laser engraving is realized across all product lines through increased quality and decreased tooling costs.

The United States Mint began replacing traditional CNC engraving with laser engraving after the first ACSYS picosecond laser was installed in 2019. Research and development continued in 2020 with the training of personnel and testing on different die steels. The Mint created its first production work dies from a laser engraved master die in 2023, and its success is the case study used to quantify the benefits of implementing laser engraving for all master tooling in 2024.

In August 2024, the Mint began the next phase of laser engraving integration; the laser engraving of work hubs for small-run numismatic programs. Removal of the master die engraving process decreased the time from design to testing by approximately 33%. Additional positive impacts were realized in the elimination of redundant processes, decreases in labor times, and the reduction of defect sources. The direct labor costs associated with producing tooling has been cut by 66%, resulting in a return on investment of 17%. Quality improvement is a difficult metric to quantify in relation to cost savings, but user-to-user variation has been reduced through the elimination of manual processes, including cleaning hubbing defects in work hubs, and machining borders into work hubs.

Direct engraving dies with the current engraving process has a ROI of approximately 9%, and will increase as cycle times continue to be reduced. The Mint anticipates a reduced cycle time of about 60% if curvature and borders are machined into the blank.

In addition to reducing the costs of coin production, laser engraving opens the door to unique designs that cannot be machined or hubbed at scale. These improvements include unique background patterns, and deeper engravings.

The United States Mint has been expanding the capabilities of laser engraving to meet the increasing demand of quick R&D timelines. Below are three projects which exemplify the added flexibility realized by using laser engraving on work dies.

FREEDOM RINGING – LIBERTY BELL COINS

Thefirst non-round coins in recent U.S. history were made by marrying the CNC and laser engraving processes. Blanks were CNC machined, then laser engraved and frosted on the Femtosecond laser. The coins feature designs with a high level of detail, seen in the fine lines of the fireworks and railing balusters, as well as individual panes of glass that were pulse forged. After dies were worn, the blanks were ground down, polished, and reburned.

LIMITED-EDITION 2.5-OUNCE SILVER FOURTH OF JULY QUARTERS

On July 4^th, 2026 (Independence Day), the Mint used the first laser engraved dies created for 2.5-ounce coins, the limited edition 2.5-ounce Silver Fourth of July Quarters. Burning these dies took approximately 17 hours. The value of laser engraving dies is two-fold: Manual cleaning time drops from approximately 8 hours to 30 minutes per die. Additionally, dies can be resurfaced and engraved many times. A program that used to take approximately 20 dies to complete, now takes 4 dies.

LIMITED-EDITION FOURTH OF JULY CIRCULATION QUARTERS

A quarter-million July 4^th cupronickel clad quarters became the first coins in circulation minted from laser engraved work dies. Producing these dies with the laser engraving process streamlined the R&D from conception through production in less than a week.

The overwhelming argument for this transition is to increase the agility of the US Mint and react to new design criteria swiftly. R&D iterations can be measured in days, instead of weeks, so prototypes are made quickly, and several design iterations can be tested before production.

Die hubbing requires large blanks with excess material to conform to the hub.

Decreasing the size of this blank for the laser engraving process decreases the raw material required to produce a die by about 20%.

There are several steps and machining processes eliminated when manufacturing laser engraved dies, benefitting the environment by reducing the use of cooling fluid and cutting byproducts.

Lastly, a study was performed on the electrical draw of a laser. The draw of one laser is less than half  the power used to engrave a die with the traditional CNC process.