| |
| US |
Diam
inches |
Diam
mm |
Circ
inches |
Circ
mm |
British |
| 1/2 |
15/32 |
11.95 |
1 31/64 |
37.60 |
A |
| 1 |
31/64 |
12.37 |
1 17/32 |
38.90 |
B |
| 1 1/2 |
1/2 |
12.78 |
1 37/64 |
40.20 |
C |
| 2 |
33/64 |
13.21 |
1 41/64 |
41.50 |
D |
| 2 1/2 |
17/32 |
13.61 |
1 11/16 |
42.70 |
E |
| 3 |
35/64 |
14.05 |
1 47/64 |
43.40 |
F |
| 3 1/2 |
9/16 |
14.45 |
1 25/32 |
44.90 |
|
| 4 |
37/64 |
14.86 |
1 27/32 |
46.50 |
H 1/2 |
| 4 1/2 |
19/32 |
15.27 |
1 57/64 |
47.80 |
I 1/2 |
| 5 |
5/8 |
15.70 |
1 15/16 |
49.00 |
J 1/2 |
| 5 1/2 |
41/64 |
16.10 |
1 63/64 |
50.30 |
L |
| 6 |
21/32 |
16.51 |
2 3/64 |
51.50 |
M |
| 6 1/2 |
43/64 |
16.92 |
2 3/32 |
52.80 |
N |
| 7 |
11/16 |
17.35 |
2 9/64 |
54.00 |
O |
| 7 1/2 |
45/64 |
17.75 |
2 13/64 |
55.30 |
P |
| 8 |
23/32 |
18.19 |
2 1/4 |
56.60 |
Q |
| 8 1/2 |
47/64 |
18.53 |
2 19/64 |
57.80 |
|
| 9 |
3/4 |
18.89 |
2 11/32 |
59.10 |
|
| 9 1/2 |
49/64 |
19.41 |
2 13/32 |
60.60 |
|
| 10 |
25/32 |
19.84 |
2 29/64 |
62.20 |
T 1/2 |
| 10 1/2 |
51/64 |
20.20 |
2 1/2 |
63.10 |
U 1/2 |
| 11 |
13/16 |
20.68 |
2 9/16 |
64.30 |
V 1/2 |
| 11 1/2 |
53/64 |
21.08 |
2 39/64 |
65.70 |
|
| 12 |
27/32 |
21.49 |
2 21/32 |
67.90 |
Y |
| 12 1/2 |
55/64 |
21.89 |
2 45/64 |
68.50 |
Z |
| 13 |
7/8 |
22.33 |
2 49/64 |
70.10 |
|
|
|