Inner Circum (mm) Inner Diam (mm) Inches UK/IE EU US FR CH JP
41 13.05 1.61 41 41 1
41.25 13.13 1.62 D 41.25 1.25
41.5 13.21 1.63 2 41.5 1.5
41.75 13.29 1.64 41.75 1.75
42 13.37 1.65 D1/2 42 42 2 2
42.25 13.45 1.66 2.25 42.25 2.25
42.5 13.53 1.67 E 42.5 2.5
42.75 13.61 1.68 2.5 42.75 2.75
43 13.69 1.69 43 43 3 3
43.25 13.77 1.7 E1/2 43.25 3.25
43.5 13.85 1.71 2.75 43.5 3.5
43.75 13.93 1.72 F 43.75 3.75
44 14.01 1.73 44 3 44 4 4
44.25 14.09 1.74 44.25 4.25
44.5 14.16 1.75 F1/2 44.5 4.5
44.75 14.24 1.76 3.25 44.75 4.75
45 14.32 1.77 G 45 45 5 5
45.25 14.4 1.78 3.5 45.25 5.25
45.5 14.48 1.79 45.5 5.5
45.75 14.56 1.8 G1/2 45.75 5.75
46 14.64 1.81 46 3.75 46 6 6
46.25 14.72 1.82 H 46.25 6.25
46.5 14.8 1.83 4 46.5 6.5
46.75 14.88 1.84 46.75 6.75
47 14.96 1.85 H1/2 47 47 7 7
47.25 15.04 1.86 4.25 47.25 7.25
47.5 15.12 1.87 I 47.5 7.5
47.75 15.2 1.88 4.5 47.75 7.75
48 15.28 1.89 48 48 8 8
48.25 15.36 1.9 I1/2 48.25 8.25
48.5 15.44 1.91 4.75 48.5 8.5
48.75 15.52 1.92 J 48.75 8.75
49 15.6 1.93 49 5 49 9 9
49.25 15.68 1.94 49.25 9.25
49.5 15.76 1.95 J1/2 49.5 9.5
49.75 15.84 1.96 5.25 49.75 9.75
50 15.92 1.97 K 50 50 10 10
50.25 16 1.98 5.5 50.25 10.25
50.5 16.07 1.99 50.5 10.5
50.75 16.15 2 K1/2 50.75 10.75
51 16.23 2.01 51 5.75 51 11 11
51.25 16.31 2.02 L 51.25 11.25
51.5 16.39 2.03 6 51.5 11.5
51.75 16.47 2.04 51.75 11.75
52 16.55 2.05 L1/2 52 52 12 12
52.25 16.63 2.06 6.25 52.25 12.25
52.5 16.71 2.07 M 52.5 12.5
52.75 16.79 2.08 6.5 52.75 12.75
53 16.87 2.09 53 53 13 13
53.25 16.95 2.1 M1/2 53.25 13.25
53.5 17.03 2.11 6.75 53.5 13.5
53.75 17.11 2.12 N 53.75 13.75
54 17.19 2.13 54 7 54 14 14
54.25 17.27 2.14 54.25 14.25
54.5 17.35 2.15 N1/2 54.5 14.5
54.75 17.43 2.16 7.25 54.75 14.75
55 17.51 2.17 O 55 55 15 15
55.25 17.59 2.18 7.5 55.25 15.25
55.5 17.67 2.19 55.5 15.5
55.75 17.75 2.2 O1/2 55.75 15.75
56 17.83 2.21 56 7.75 56 16 16
56.25 17.9 2.22 P 56.25 16.25
56.5 17.98 2.23 8 56.5 16.5
56.75 18.06 2.24 56.75 16.75
57 18.14 2.25 P1/2 57 57 17 17
57.25 18.22 2.26 8.25 57.25 17.25
57.5 18.3 2.27 Q 57.5 17.5
57.75 18.38 2.28 8.5 57.75 17.75
58 18.46 2.29 58 58 18 18
58.25 18.54 2.3 Q1/2 58.25 18.25
58.5 18.62 2.31 8.75 58.5 18.5
58.75 18.7 2.32 R 58.75 18.75
59 18.78 2.33 59 9 59 19 19
59.25 18.86 2.34 59.25 19.25
59.5 18.94 2.35 R1/2 59.5 19.5
59.75 19.02 2.36 9.25 59.75 19.75
60 19.1 2.37 S 60 60 20 20
60.25 19.18 2.38 9.5 60.25 20.25
60.5 19.26 2.39 60.5 20.5
60.75 19.34 2.4 S1/2 60.75 20.75
61 19.42 2.41 61 9.75 61 21 21
61.25 19.5 2.42 T 61.25 21.25
61.5 19.58 2.43 10 61.5 21.5
61.75 19.66 2.44 61.75 21.75
62 19.74 2.45 T1/2 62 62 22 22
62.25 19.81 2.46 10.25 62.25 22.25
62.5 19.89 2.47 U 62.5 22.5
62.75 19.97 2.48 10.5 62.75 22.75
63 20.05 2.49 63 63 23 23
63.25 20.13 2.5 U1/2 63.25 23.25
63.5 20.21 2.51 10.75 63.5 23.5
63.75 20.29 2.52 V 63.75 23.75
64 20.37 2.53 64 11 64 24 24
64.25 20.45 2.54 64.25 24.25
64.5 20.53 2.55 V1/2 64.5 24.5
64.75 20.61 2.56 11.25 64.75 24.75
65 20.69 2.57 W 65 65 25 25
65.25 20.77 2.58 11.5 65.25 25.25
65.5 20.85 2.59 65.5 25.5
65.75 20.93 2.6 W1/2 65.75 25.75
66 21.01 2.61 66 11.75 66 26 26
66.25 21.09 2.62 X 66.25 26.25
66.5 21.17 2.63 12 66.5 26.5
66.75 21.25 2.64 66.75 26.75
67 21.33 2.65 X1/2 67 67 27 27
67.25 21.41 2.66 12.25 67.25 27.25
67.5 21.49 2.67 Y 67.5 27.5
67.75 21.57 2.68 12.5 67.75 27.75
68 21.65 2.69 68 68 28 28
68.25 21.72 2.7 Y1/2 68.25 28.25
68.5 21.8 2.71 12.75 68.5 28.5
68.75 21.88 2.72 Z 68.75 28.75