September 1998

Dollar Coin - Design and Materials

Copper Applications in General Interest

By Dr. John G. Cowie


The second US Mint's stakeholders' meeting was held on Wednesday, August 12, 1998 in Washington D.C. It was chaired by Andrew Cosgarea, Jr. Associate Director, Chief Operating Officer of the United States Mint. The purpose of the meeting was to brief the Coin Coalition (a group which promotes the introduction of a new dollar coin) and other interested parties on the technical aspects of the new dollar coin including the alloy design. The Mint desires the introduction of a dollar coin that becomes widely accepted by the public. The Mint does not want another "token" dollar coin like the Susan B. Anthony (SBA) or the Eisenhower dollars.

Physical Attributes
With the exception of color and edge, the new dollar coin will be identical to the SBA, i.e., same diameter, weight and thickness. The color of the new dollar coin will be golden ranging between that for 14 karat and 22 karat gold. The edge will be plain as opposed to the reed-edged quarter with a wider border than that for the SBA.

The dollar coin will be a clad metal composite in order to have a unique electromagnetic signature that can be automatically measured with coin vending machines. Roll bonded metals or clad coins are much more difficult to counterfeit. The Mint considers security of paramount importance.

The coin and its components (strip & blanks) must be manufactured within the United States.

The design of the obverse and reverse of the coin have been decided. The obverse will depict Sacajawea, Louis and Clark's Native American guide. The reverse will feature a bald eagle.

Replacement for the SBA
The new dollar coin will replace the SBA on January 1, 2000. However, existing SBAs will remain in circulation. There is a possibility that the Mint will run out of SBAs before that date due to increasing demand from the US Postal Office and the NY City Transit Authority. Current projections indicate that the Mint may need to produce new SBAs for three months beginning in October 1999.

Possible Replacement for the Paper Dollar
Economics dictate that the paper dollar or note be replaced by the dollar coin. The dollar note costs the US Treasury approximately 4 cents and the dollar coin costs approximately 8 cents to produce. The paper note lasts on-average 14 months, whereas coinage remains in circulation between 20 and 30 years. However, the success of the dollar coin in terms of public acceptance will determine whether or not the dollar note is replaced. Success is defined by the Mint as "extensively used at the retail level." No decision has been made to replace the dollar note.

Copper Volume Potentials
The Mint expects to produce between 50 and 200 million coins in the first year, 2000. This translates to between 1.4 and 5.5 million pounds of composite clad strip including an approximate 25% scrap rate. Should the dollar note be withdrawn from circulation, The Mint predicts that they will need to produce approximately 10.5 billion coins in three years. This translates into 290 million pounds of clad strip over the three years (97 million pounds per year) which includes the 25% scrap rate.


  • Secretary of the Treasury approved the design concept (Sacajawea) - July 29, 1998.
  • Secretary approves the final designs - January 8, 1999.
  • Final Alloy Selection - February 26, 1999.
  • Begin production of the proof coins - July 1999.
  • Begin production of the dollar coins - October 1999.
  • Deliveries to the Federal Reserve Banks - January 2000.
The Mint is requiring a composite system consisting of a golden colored cladding on a copper or copper alloy core. Three clad materials that meet the color requirement include:
  • PMX 914 Golden Nordic.
  • Olin 894 Modified (low nickel) British Pound.
  • Olin 884 Tin Brass.

The Mint prefers the Golden Nordic due to its superior properties (color, wear, tarnish resistance and electromagnetic characteristics). However, the Golden Nordic does not bond well to the copper core and is at present considered unacceptable. The Mint has asked the strip manufacturers to try to improve the bonding strength through processing improvements.

The modified (low nickel) British Pound clad metal exhibits good properties (color, wear, tarnish resistance and electromagnetic characteristics). The bonding strength of this clad system is excellent.

The tin brass clad metal also exhibits good properties with the exception of tarnish resistance which is "fair."

The Mint will not announce their selection of the material-system for the cladding and core until February 26, 1999.

Key Dates

  • August 26, 1998 - Security/Technical Working Session.
  • February 26, 1999 - Target date to select alloy for Phase 3.
Future Activities
  • Continue ongoing anti-counterfeiting design efforts.
  • Complete process development at the Philadelphia Mint for circulating coinage.
  • Begin process development at the San Francisco Mint for numismatic (proof) quality coinage.
The next dollar coin stakeholders' meeting is tentatively scheduled to be held in 4 to 6 months.

Additional Information
Comments and questions can be sent to the US Mint via email to [email protected] and the US Mint web site may be viewed at

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