27 mm diameter, 6.47 grams (100 grains), plain edge with center hole
1927,1933,1934,1935,1937,1939,1940,1941,1942 Cupronickel alloy (75% copper and 25% nickel)
1942,1943 Bronze alloy (97% copper, 2.5% zinc, and 0.5% tin)
1946,1947 Cupronickel alloy (75% copper and 25% nickel)