Landmark Is in Mint Condition as It Turns 50

Because it is surrounded by a 10-foot fence and by guards, “many people think this place is a prison,” said Thomas Miller, officer in charge of the gray-granite building just off Market Street north of the Mission District. “We try to keep a low profile.”

Carved in stone over the front doors, however, are the words E PLURIBUS UNUM.

The San Francisco Mint will be 50 years old on Friday, and on that day, for the first time since it began stamping out coins in 1937, visitors will be allowed to tour the production floor. A total of 2,100 will be admitted that day only in groups of 35.

Reservations must be made in advance by calling the mint.

Because circulated coins are not presently being stamped out by the San Francisco Mint, visitors will see the production of coin proof sets--each containing a penny, a nickel, dime, quarter and half-dollar and each set selling for $11.

Last year, Miller said, more than 3 million proof sets were sold to collectors, bringing the government a $12.3-million profit.

The quality of coin proof sets is higher than that of coins intended for general circulation, such as those presently being manufactured at the Denver and Philadelphia mints. Coin proof blanks are burnished with thousands of steel beads and cleaning chemicals that buff out imperfections and polish surfaces to mirror texture. Further, they are heated to as much as 1,600 degrees, cooled with water, then hand dried with towels by workers who wear gloves to avoid leaving fingerprints. The mint has its own laundry, washing 10,000 towels a day.

The coin blanks are hand-fed one at a time with tweezers to a slow- moving press and stamped at least twice--often three times--to produce a sharper impression.

Also being produced at the San Francisco Mint are one-ounce bullion American eagle silver dollars. The coin’s price fluctuates on a daily basis, depending on the price of silver, and is sold by the government for that amount plus $1 on the day of sale. It is the first time the government has minted bullion coins with fluctuating prices.

Since last November, when Treasury Secretary James A. Baker was here to strike the first of the silver eagles with a shout of, “Hi-ho, Silver, away!” 9 million of them have been sold.

In addition, the mint is turning out proof coins of the American eagle silver dollar. A total of 1.4 million 1986 eagle proofs are being struck for sale at a fixed price of $21 each. When that run is finished, production of the 1987 silver eagle proofs will begin.

“We are working shifts around the clock to produce the silver eagle and cannot keep up with the demand,” Miller said.

Going into production next month at the mint will be a commemorative silver dollar marking the 200th anniversary of the signing of the U.S. Constitution.

The San Francisco Mint is often called “the new mint” because it is the third in this city since 1854. “The old mint,” which produced coins from 1874 to 1937 and survived the earthquake of 1906, is now a museum.

Visitors on Friday will find that they must empty their pockets of coins before they enter--something the 800 men and women who work there must do every day.

They cannot come out with any, either.