| American |
British |
European |
Inside Diameter (mm) |
|---|
|
A |
|
12.065 |
|
|
38 |
12.096 |
|
A½ |
|
12.263 |
| 1 |
|
|
12.344 |
|
|
39 |
12.344 |
|
B |
|
12.459 |
|
B½ |
|
12.657 |
|
|
40 |
12.733 |
| 1½ |
|
|
12.751 |
|
C |
|
12.852 |
|
C½ |
41 |
13.051 |
| 2 |
|
|
13.157 |
|
D |
|
13.246 |
|
|
42 |
13.369 |
|
D½ |
|
13.444 |
| 2½ |
|
|
13.564 |
|
E |
|
13.640 |
|
|
43 |
13.687 |
|
E½ |
|
13.838 |
| 3 |
|
|
13.970 |
|
|
44 |
14.006 |
|
F |
|
14.034 |
|
F½ |
|
14.232 |
|
|
45 |
14.324 |
| 3½ |
|
|
14.376 |
|
G |
|
14.427 |
|
G½ |
|
14.625 |
|
|
46 |
14.642 |
| 4 |
|
|
14.783 |
|
H |
|
14.821 |
|
|
47 |
14.961 |
|
H½ |
|
15.019 |
| 4½ |
|
|
15.189 |
|
I |
|
15.215 |
|
|
48 |
15.279 |
|
I½ |
|
15.413 |
| 5 |
|
49 |
15.597 |
|
J |
|
15.608 |
|
J½ |
|
15.806 |
|
|
50 |
15.916 |
| 5½ |
K |
|
16.002 |
|
K½ |
|
16.200 |
|
|
51 |
16.234 |
| 6 |
L |
|
16.396 |
|
|
52 |
16.552 |
|
L½ |
|
16.594 |
|
M |
|
16.789 |
| 6½ |
|
|
16.815 |
|
|
53 |
16.871 |
|
M½ |
|
16.988 |
|
N |
|
17.183 |
|
|
54 |
17.189 |
| 7 |
|
|
17.221 |
|
N½ |
|
17.381 |
| 55 |
|
|
17.507 |
|
O |
|
17.577 |
| 7½ |
|
|
17.628 |
|
O½ |
|
17.775 |
|
|
56 |
17.826 |
|
P |
|
17.971 |
| 8 |
|
|
18.034 |
|
|
57 |
18.144 |
|
P½ |
|
18.169 |
|
Q |
|
18.364 |
| 8½ |
|
|
18.453 |
|
|
58 |
18.462 |
|
Q½ |
|
18.562 |
|
R |
|
18.758 |
|
|
59 |
18.780 |
| 9 |
|
|
18.872 |
|
R½ |
|
18.956 |
|
|
60 |
19.098 |
|
S |
|
19.152 |
|
|
60 |
19.098 |
| 9½ |
|
|
19.279 |
|
S½ |
|
19.350 |
|
|
61 |
19.416 |
|
T |
|
19.545 |
|
T½ |
|
19.741 |
| 10 |
|
|
19.761 |
|
U |
|
19.939 |
|
|
63 |
20.054 |
|
U½ |
|
20.137 |
| 10½ |
|
|
20.168 |
|
V |
|
20.333 |
|
|
64 |
20.372 |
|
V½ |
|
20.531 |
| 11 |
|
|
20.599 |
|
|
65 |
20.690 |
|
W |
|
20.726 |
|
W½ |
|
20.925 |
| 11½ |
|
66 |
21.008 |
|
X |
|
21.120 |
|
X½ |
|
21.318 |
|
|
67 |
21.326 |
| 12 |
|
|
21.412 |
|
Y |
|
21.514 |
|
|
68 |
21.645 |
|
Y½ |
|
21.712 |
| 12½ |
|
|
21.819 |
|
Z |
|
21.908 |
|
|
69 |
21.963 |
|
Z½ |
|
22.106 |
| 13 |
|
|
22.252 |
|
