Inside Diameter (mm)
Inside Circumfrance (Inches)
Sizes (mm)
Europe, UK & Australia
USA & Canada
France & Russia
Germany
Japan
Switzerland
9.91
0.39
31.13
-
0
-
-
-
-
10.72
0.442
33.68
-
0
-
-
-
-
11.53
0.454
36.22
-
0
-
-
-
-
11.95
0.474
37.54
A
01-Feb
-
-
-
-
12.18
0.482
38.26
A 1/2
03-Apr
-
-
-
-
12.37
0.487
38.86
B
1
-
-
1
-
12.6
0.496
39.58
B 1/2
1 1/4
-
-
-
-
12.78
0.503
40.15
C
1 1/2
-
-
-
-
13
0.512
40.84
C 1/2
1 3/4
-
-
-
-
13.21
0.52
41.5
D
2
41 1/2
13 1/2
2
1 1/2
13.41
0.528
42.13
D 1/2
2 1/4
-
-
-
-
13.61
0.536
42.76
E
2 1/2
42 3/4
13 3/4
3
2 3/4
13.83
0.544
43.45
E 1/2
2 3/4
-
-
-
-
14.05
0.553
44.14
F
3
44
14
4
4
14.15
0.557
44.45
F 1/2
3 1/8
-
-
-
-
14.25
0.561
44.77
F 3/4
3 1/4
-
-
-
-
14.36
0.565
45.11
G
3 3/8
45 1/4
-
5
5 1/4
14.45
0.569
45.4
G 1/4
3 1/2
-
14 1/2
-
-
14.56
0.573
45.74
G 1/2
3 5/8
-
-
6
-
14.65
0.577
46.02
H
3 3/4
46 1/2
-
-
6 1/2
14.86
0.585
46.68
H 1/2
4
-
15
7
-
15.04
0.592
47.25
I
4 1/4
47 3/4
-
-
7 3/4
15.27
0.601
47.97
I 1/2
4 1/2
-
15 1/4
8
-
15.4
0.606
48.38
J
4 5/8
49
15 1/2
-
9
15.53
0.611
48.79
J 1/4
4 3/4
-
-
-
-
15.7
0.618
49.32
J 1/2
5
-
15 3/4
9
-
15.8
0.622
49.64
K
5 1/8
50
-
-
10
15.9
0.626
49.95
K 1/4
5 1/4
-
-
-
-
16
0.63
50.27
K 1/2
5 3/8
-
-
10
-
16.1
0.634
50.58
L
5 1/2
51 3/4
16
-
11 3/4
16.3
0.642
51.21
L 1/4
5 3/4
-
-
-
-
16.41
0.646
51.55
L 1/2
5 7/8
-
-
-
-
16.51
0.65
51.87
M
6
52 3/4
16 1/2
12
12 3/4
16.71
0.658
52.5
M 1/2
6 1/4
-
-
-
-
16.92
0.666
53.16
N
6 1/2
54
17
13
14
17.13
0.674
53.82
N 1/2
6 3/4
-
-
-
-
17.35
0.683
54.51
O
7
55 1/4
17 1/4
14
15 1/4
17.45
0.687
54.82
O 1/2
7 1/4
-
-
-
-
17.75
0.699
55.76
P
7 1/2
56 1/2
17 3/4
15
16 1/2
17.97
0.707
56.45
P 1/2
7 3/4
-
-
-
-
18.19
0.716
57.15
Q
8
57 3/4
18
16
17 3/4
18.35
0.722
57.65
Q 1/2
8 1/4
-
-
-
-
18.53
0.729
58.21
Q 3/4
8 1/2
-
18 1/2
17
-
18.61
0.733
58.47
R
8 5/8
59
-
-
19
18.69
0.736
58.72
R 1/4
8 3/4
-
-
-
-
18.8
0.74
59.06
R 1/2
8 7/8
-
-
-
-
18.89
0.748
59.34
R 3/4
9
-
19
18
-
19.1
0.752
60
S
9 1/8
60 1/4
-
-
20 1/4
19.22
0.757
60.38
S 1/4
9 1/4
-
-
-
-
19.31
0.76
60.66
S 1/2
9 3/8
-
-
-
-
19.41
0.764
60.98
S 3/4
9 1/2
-
19 1/2
19
-
19.51
0.768
61.29
T
9 5/8
61 1/2
-
-
21 1/2
19.62
0.772
61.64
T 1/4
9 3/4
-
-
-
-
19.84
0.781
62.33
T 1/2
10
-
20
20
-
20.02
0.788
62.89
U
10 1/4
62 3/4
-
21
22 3/4
20.2
0.797
63.46
U 1/2
10 1/2
-
20 1/4
22
-
20.32
0.8
63.84
V
10 5/8
63
-
-
23 3/4
20.44
0.805
64.21
V 1/4
10 3/4
-
-
-
-
20.68
0.814
64.97
V 1/2
11
-
20 3/4
23
-
20.76
0.817
65.22
W
11 1/8
65
-
-
25
20.85
0.821
65.5
W 1/4
11 1/4
-
-
-
-
20.94
0.824
65.78
W 1/2
11 3/8
-
-
-
-
21.08
0.83
66.22
W 3/4
11 1/2
-
21
24
-
21.18
0.834
66.54
X
11 5/8
66 1/4
-
-
26 1/4
21.24
0.836
66.73
X 1/4
11 3/4
-
-
-
-
21.3
0.839
66.92
X 1/2
11 7/8
-
-
-
-
21.49
0.846
67.51
Y
12
67 1/2
21 1/4
25
27 1/2
21.69
0.854
68.14
Y 1/2
12 1/4
-
-
-
-
21.89
0.862
68.77
Z
12 1/2
68 3/4
21 3/4
26
28 3/4
22.1
0.87
69.43
Z +1/2
12 3/4
-
-
-
-
22.33
0.879
70.15
Z+1
13
-
22
27
-
22.6
0.89
71
Z+1.5
13.5
-
-
-