AB
1
Ring Diameter (MM)USA/Canada
2
14.0 mm.3
3
14.4 mm.3½
4
14.8 mm.4
5
15.2 mm.4½
6
15.6 mm.5
7
16.0 mm.5½
8
16.5 mm.6
9
16.9 mm.6½
10
17.3 mm.7
11
17.7 mm.7½
12
18.2 mm.8
13
18.6 mm.8½
14
19.0 mm.9
15
19.4 mm.9½
16
19.8 mm.10
17
20.2 mm.10½
18
20.6 mm.11
19
21.0 mm.11½
20
21.4 mm.12
21
21.8 mm.12½
22
22.2 mm.13
23
22.6 mm.13½