Inside Diameter(MM)
Inside Circum.(MM)
US &CA
UK &AUS &NZ
IT &SP &SW
14.88
46.8
4
H
6.75
15.09
47.4
4¼
H½
7.5
15.49
48.7
4¾
J
8.75
15.7
49.3
5
J½
9.25
15.9
50
5¼
K
10
16.31
51.2
5¾
L
11.25
16.51
51.9
6
L½
11.75
16.71
52.5
6¼
M
12.5
17.12
53.8
6¾
N
13.75
17.32
54.4
7
N½
14.5
17.53
55.1
7¼
O
15
17.93
56.3
7¾
P
16.25
18.14
57
8
P½
17
18.34
57.6
8¼
Q
17.5
18.75
58.9
8¾
R
19
18.95
59.5
9
R½
19.5
19.15
60.2
9¼
S
20.25
19.56
61.4
9¾
T
21.5
19.76
62.1
T½
22
20.57
64.6
11
V½
24.75
21.39
67.2
12
X½
27.25