US / Canada Standard

Average Diameter In Inches

British Equivalent

French Equivalent

German Equivalent

Japanese Equivalent

Swiss Equivalent

3

.553

F

44

14

4

4

3 1/8

-

F-1/2

-

-

-

-

3 3/8

-

G

45 1/4

-

5

5 1/4

3 1/2

.569

-

-

14 1/2

-

-

3 5/8

-

G-1/2

-

-

6

-

3 3/4

-

H

46 1/2

-

-

6 1/2

4

.585

H-1/2

-

15

7

-

4 1/4

-

I

47 3/4

-

-

7 3/4

4 1/2

.601

I-1/2

-

15 1/4

8

-

4 7/8

-

J

49

-

-

9

5

.618

J-1/2

-

15 3/4

9

-

5 1/8

-

K

50

-

-

10

5 3/8

-

K-1/2

-

-

10

-

5 1/2

.634

L

51 3/4

16

-

11 3/4

5 7/8

-

L-1/2

-

-

11

-

6

.650

M

52 3/4

16 1/2

12

12 3/4

6 1/4

-

M-1/2

-

-

-

-

6 1/2

.666

N

54

17

13

14

6 3/4

-

N-1/2

-

-

-

7

.683

O

55 1/4

17 1/4

14

15 1/4

7 1/4

-

O-1/2

-

-

-

-

7 1/2

.699

P

56 1/2

17 3/4

15

16 1/2

7 3/4

-

P-1/2

-

-

-

-

8

.716

Q

57 3/4

18

16

17 3/4

8 1/4

-

Q-1/2

-

-

-

-

8 1/2

.732

-

-

18 1/2

17

-

8 5/8

-

R

59

-

-

19

8 7/8

-

R-1/2

-

-

-

-

9

.748

-

-

19

18

-

9 1/8

-

S

60 1/4

-

-

20 1/4

9 3/8

-

S-1/2

-

-

-

-

9 1/2

.764

-

-

19 1/2

19

-

9 5/8

-

T

61 1/2

-

-

21 1/2

10

.781

T-1/2

-

20

20

-

10 1/4

-

U

62 3/4

-

21

22 3/4

10 1/2

.797

U-1/2

-

20 1/4

22

-

10 5/8

-

V

63 3/4

-

-

23 3/4

11

.814

V-1/2

-

20 3/4

23

-

11 1/8

-

W

65

-

-

25

11 3/8

-

W-1/2

-

-

-

-

11 1/2

.830

-

-

21

24

-

11 5/8

-

X

66 1/4

-

-

26 1/4

11 7/8

-

X-1/2

-

-

-

-

12

.846

Y

67 1/2

21 1/4

25

27 1/2

12 1/4

-

Y-1/2

-

-

-

-

12 1/2

.862

Z

68 3/4

21 3/4

26

28 3/4

12 3/4

-

Z-1/2

-

-

-