United States Coin Chart
Diameter Coins   Direct Fit     Ring Fit  
13mm Gold $1 (Type 1) n/a 13mm
14mm Silver Three Cent n/a 14mm
15mm Half Dimes (1829~1873), Commemorative Gold $1,
Gold $1 (1854~1889 Type 2 & 3)
n/a 15mm
16mm Half Dimes (1794~1805) 16.5mm
(loose fit)
16.5mm $5 1/10oz American Gold Eagle,
$10 1/10oz Platinum Eagle
16.5mm 16mm
17.9mm US Dimes (1829-present), Nickel Three Cent,
$2.50 Indian Gold Quarter Eagle
18mm 18mm
18.2mm Gold $2.50 Capped Head to Left (reduced
diameter) (1829~1839)
n/a 18mm
18.5mm Gold $2.50 Capped Head to Left (1829~1834) n/a 18mm
19mm US Cents (1858-present), Bust Dime (1796~1828) 19mm 19mm
19.2mm 1/10oz Silver Walking Liberty n/a 19mm
20mm Shield Nickel, Gold $2.50 (1796~1828), $3 Gold,
1/10oz Kennedy Half Dollar
n/a 20mm
21.2mm US Nickels (Liberty Nickel, Buffalo Nickel, Jefferson Nickel 21.2mm 21mm
21.6mm $5 Indian Gold Half Eagle n/a 21mm