Size Guide

Inside Diameter

Inside Circumference

Sizes

MM

Inches

MM

Inches

British & Australian

US & Canada

French & Russian

German

Japanese

Swiss

9.91

0.390

31.13

1.22

-

0

-

-

-

-

10.72

0.442

33.68

1.39

-

0

-

-

-

-

11.53

0.454

36.22

1.43

-

0

-

-

-

-

11.95

0.474

37.54

1.49

A

1/2

-

-

-

-

12.18

0.482

38.26

1.51

A 1/2

3/4

-

-

-

-

12.37

0.487

38.86

1.53

B

1

-

-

1

-

12.60

0.496

39.58

1.56

B 1/2

1 1/4

-

-

-

-

12.78

0.503

40.15

1.58

C

1 1/2

-

-

-

-

13.00

0.512

40.84

1.61

C 1/2

1 3/4

-

-

-

-

13.21

0.520

41.50

1.63

D

2

41 1/2

13 1/2

2

1 1/2

13.41

0.528

42.13

1.66

D 1/2

2 1/4

-

-

-

-

13.61

0.536

42.76

1.68

E

2 1/2

42 3/4

13 3/4

3

2 3/4

13.83

0.544

43.45

1.71

E 1/2

2 3/4

-

-

-

-

14.05

0.553

44.14

1.74

F

3

44

14

4

4

14.15

0.557

44.45

1.75

F 1/2

3 1/8

-

-

-

-

14.25

0.561

44.77

1.76

F 3/4

3 1/4

-

-

-

-

14.36

0.565

45.11

1.77

G

3 3/8

45 1/4

-

5

5 1/4

14.45

0.569

45.40

1.79

G 1/4

3 1/2

-

14 1/2

-

-

14.56

0.573

45.74

1.80

G 1/2

3 5/8

-

-

6

-

14.65

0.577

46.02

1.81

H

3 3/4

46 1/2

-

-

6 1/2

14.86

0.585

46.68

1.84

H 1/2

4

-

15

7

-

15.04

0.592

47.25

1.86

I

4 1/4

47 3/4

-

-

7 3/4

15.27

0.601

47.97

1.89

I 1/2

4 1/2

-

15 1/4

8

-

15.40

0.606

48.38

1.90

J

4 5/8

49

15 1/2

-

9

15.53

0.611

48.79

1.92

J 1/4

4 3/4

-

-

-

-

15.70

0.618

49.32

1.94

J 1/2

5

-

15 3/4

9

-

15.80

0.622

49.64

1.95

K

5 1/8

50

-

-

10

15.90

0.626

49.95

1.97

K 1/4

5 1/4

-

-

-

-

16.00

0.630

50.27

1.98

K 1/2

5 3/8

-

-

10

-

16.10

0.634

50.58

1.99

L

5 1/2

51 3/4

16

-

11 3/4

16.30

0.642

51.21

2.02

L 1/4

5 3/4

-

-

-

-

16.41

0.646

51.55

2.03

L 1/2

5 7/8

-

-

-

-

16.51

0.650

51.87

2.04

M

6

52 3/4

16 1/2

12

12 3/4

16.71

0.658

52.50

2.07

M 1/2

6 1/4

-

-

-

-

16.92

0.666

53.16

2.09

N

6 1/2

54

17

13

14

17.13

0.674

53.82

2.12

N 1/2

6 3/4

-

-

-

-

17.35

0.683

54.51

2.15

O

7

55 1/4

17 1/4

14

15 1/4

17.45

0.687

54.82

2.16

O 1/2

7 1/4

-

-

-

-

17.75

0.699

55.76

2.20

P

7 1/2

56 1/2

17 3/4

15

16 1/2

17.97

0.707

56.45

2.22

P 1/2

7 3/4

-

-

-

-

18.19

0.716

57.15

2.25

Q

8

57 3/4

18

16

17 3/4

18.35

0.722

57.65

2.27

Q 1/2

8 1/4

-

-

-

-

18.53

0.729

58.21

2.29

Q 3/4

8 1/2

-

18 1/2

17

-

18.61

0.733

58.47

2.30

R

8 5/8

59

-

-

19

18.69

0.736

58.72

2.31

R 1/4

8 3/4

-

-

-

-

18.80

0.740

59.06

2.32

R 1/2

8 7/8

-

-

-

-

18.89

0.748

59.34

2.35

R 3/4

9

-

19

18

-

19.10

0.752

60.00

2.36

S

9 1/8

60 1/4

-

-

20 1/4

19.22

0.757

60.38

2.38

S 1/4

9 1/4

-

-

-

-

19.31

0.760

60.66

2.39

S 1/2

9 3/8

-

-

-

-

19.41

0.764

60.98

2.40

S 3/4

9 1/2

-

19 1/2

19

-

19.51

0.768

61.29

2.41

T

9 5/8

61 1/2

-

-

21 1/2

19.62

0.772

61.64

2.43

T 1/4

9 3/4

-

-

-

-

19.84

0.781

62.33

2.45

T 1/2

10

-

20

20

-

20.02

0.788

62.89

2.48

U

10 1/4

62 3/4

-

21

22 3/4

20.20

0.797

63.46

2.50

U 1/2

10 1/2

-

20 1/4

22

-

20.32

0.800

63.84

2.51

V

10 5/8

63

-

-

23 3/4

20.44

0.805

64.21

2.53

V 1/4

10 3/4

-

-

-

-

20.68

0.814

64.97

2.56

V 1/2

11

-

20 3/4

23

-

20.76

0.817

65.22

2.57

W

11 1/8

65

-

-

25

20.85

0.821

65.50

2.58

W 1/4

11 1/4

-

-

-

-

20.94

0.824

65.78

2.59

W 1/2

11 3/8

-

-

-

-

21.08

0.830

66.22

2.61

W 3/4

11 1/2

-

21

24

-

21.18

0.834

66.54

2.62

X

11 5/8

66 1/4

-

-

26 1/4

21.24

0.836

66.73

2.63

X 1/4

11 3/4

-

-

-

-

21.30

0.839

66.92

2.64

X 1/2

11 7/8

-

-

-

-

21.49

0.846

67.51

2.66

Y

12

67 1/2

21 1/4

25

27 1/2

21.69

0.854

68.14

2.68

Y 1/2

12 1/4

-

-

-

-

21.89

0.862

68.77

2.71

Z

12 1/2

68 3/4

21 3/4

26

28 3/4

22.10

0.870

69.43

2.73

Z +1/2

12 3/4

-

-

-

-

22.33

0.879

70.15

2.76

Z+1

13

-

22

27

-

22.60

0.890

71.00

2.80

Z+1.5

13.5

-

-

-

-