1940-S

San Francisco produced 21,560,000 Mercury Dimes in 1940, a figure very close to the Denver output for the same year and reflective of growing demand for small denominations on the West Coast. The mint operated at a steady pace as defense spending began to ramp up ahead of America's entry into World War II. These dimes circulated through the war years and beyond, and most surviving examples show wear consistent with long service in commerce. Original Mint State rolls reached collector hands through the 1950s and 1960s, providing enough high-grade material to make this date accessible at most levels of the market.

The Weinman design carries Liberty in a winged Phrygian cap on the obverse, often confused with Mercury but actually representing the freedom of thought. The reverse features a fasces with an axe at the top, diagonal thong wrapping, and an olive branch, with the S mintmark at the left of the fasces base. Specifications match the rest of the series at 2.5 grams in 90% silver and 10% copper, 17.9 mm diameter, and reeded edge. Authenticators verify the S punch style, which by 1940 was the knob-end S used throughout the late series at San Francisco. The central bands on the fasces must show complete horizontal separation to earn the Full Bands designation from PCGS or NGC, and 1940-S usually strikes well enough that Full Bands examples surface regularly.

This is an affordable date through MS-66 Full Bands, with prices stepping up at MS-67. Heritage Auctions has shown strong results for top examples but nothing extreme. For most collectors this is a comfortable slot. Buyers should match expected prices against current Heritage Auctions and Stack's Bowers Galleries records before committing to a purchase. Collectors building a date-and-mintmark set should keep an eye on registry-set premiums when assessing comparable certified examples. The Mercury Dime series history offers further reading.