US Size
Dia. -inch
Dia. in MM
Metric -MM
British
French
German
Japanese
Swiss
0000
.390
9.91
-
00
.422
10.72
0
.454
11.53
1/2
.474
11.95
A
3/4
.482
12.18
A 1/2
1
.487
12.37
38.9
B
1 1/4
12.60
39.6
B 1/2
1 1/2
.503
12.78
40.2
C
1 3/4
13.00
40.8
C 1/2
2
.520
13.21
41.5
D
41 1/2
13 1/2
2 1/4
13.41
42.1
D 1/2
2 1/2
.536
13.61
42.7
E
42 3/4
13 3/4
3
2 3/4
13.83
43.4
E 1/2
.553
14.05
44.0
F
44
14
4
3 1/8
14.15
44.3
F 1/2
3 1/4
14.25
44.6
3 3/8
14.36
44.9
G
45 1/4
5
5 1/4
3 1/2
.569
14.45
45.2
14 1/2
3 5/8
14.56
45.6
G 1/2
6
3 3/4
14.65
45.9
H
46 1/2
6 1/2
.585
14.86
46.5
H 1/2
15
7
4 1/4
15.04
47.1
I
47 3/4
7 3/4
4 1/2
.601
15.27
47.8
I 1/2
15 1/4
8
4 5/8
15.40
48.1
J
49
15 1/2
9
4 3/4
15.53
48.4
.618
15.70
49.0
J 1/2
15 3/4
5 1/8
15.80
49.3
K
50
10
15.90
49.6
5 3/8
16.0
50.0
K 1/2
5 1/2
.634
16.10
50.3
L
51 3/4
16
11 3/4
5 3/4
16.30
50.9
5 7/8
16.41
51.3
L 1/2
.650
16.51
51.5
M
52 3/4
16 1/2
12
12 3/4
6 1/4
16.71
52.2
M 1/2
.666
16.92
52.8
N
54
17
13
6 3/4
17.13
53.4
N 1/2
.683
17.35
54.0
O
55 1/4
17 1/4
7 1/4
17.45
54.7
O 1/2
7 1/2
.699
17.75
55.3
P
56 1/2
17 3/4
17.97
55.9
P 1/2
.716
18.19
56.6
Q
57 3/4
18
8 1/4
18.35
57.2
Q 1/2
8 1/2
.732
18.53
57.8
18 1/2
8 5/8
18.61
58.4
R
59
19
8 3/4
18.69
8 7/8
18.80
59.0
R 1/2
.748
18.89
59.1
9 1/8
19.10
59.4
S
60 1/4
20 1/4
9 1/4
19.22
59.7
9 3/8
19.31
60.0
S 1/2
9 1/2
.764
19.41
60.3
19 1/2
9 5/8
19.51
60.6
T
61 1/2
21 1/2
9 3/4
19.62
60.9
.781
19.84
61.6
T 1/2
20
10 1/4
20.02
62.2
U
62 3/4
21
22 3/4
10 1/2
.797
20.20
62.8
U 1/2
22
10 5/8
20.32
63.1
V
63
23 3/4
10 3/4
20.44
63.5
11
.814
20.68
64.1
V 1/2
20 3/4
23
11 1/8
20.76
64.3
W
65
25
11 1/4
20.85
64.7
11 3/8
20.94
65.0
W 1/2
11 1/2
21.08
65.3
24
11 5/8
.830
21.18
65.7
X
66 1/4
26 1/4
21.24
66.0
11 7/8
21.30
66.3
X 1/2
.846
21.49
66.6
Y
67 1/2
21 1/4
27 1/2
12 1/4
21.69
67.2
Y 1/2
12 1/2
.862
21.89
67.9
Z
68 3/4
21 3/4
26
28 3/4
22.10
68.5
Z 1/2
.879
22.33
69.1
27
