In 1970, Case added ten dots beneath the U.S.A. on all knife tangs. Each year a dot was removed. The same dating system was used during the 1980s. The differences are the “lightning” form of the letter S in Case and USA and the fact that the dots were put above the USA.

How old is a case knife with 9 dots?

For clarification, note that ten dots appear on 1970 knives, nine dots appear in 1971 knives, eight on 1972 knives, and so on. Throughout the 1980s, Case used the same dating system as the 70s. 1980 knives have 10 dots, and one is removed each year.