| NZ, Australia, UK | USA, Canada | Asia | Europe | Inside Diameter (mm) |
| A | ½ | – | – | 12.04 |
| A ½ | ¾ | – | – | 12.24 |
| B | 1 | 1 | – | 12.37 |
| B ½ | 1 ¼ | – | – | 12.65 |
| C | 1 ½ | – | – | 12.85 |
| C ½ | 1 ¾ | – | – | 13.06 |
| D | 2 | 2 | 1 ½ | 13.26 |
| D ½ | 2 ¼ | – | – | 13.46 |
| E | 2 ½ | 3 | 2 ¾ | 13.66 |
| E ½ | 2 ¾ | – | – | 13.87 |
| F | 3 | 4 | 3 | 14.07 |
| F ½ | 3 1/8 | – | – | 14.17 |
| G | 3 3/8 | 5 | 5 ¼ | 14.38 |
| G ½ | 3 5/8 | 6 | – | 14.58 |
| H | 3 ¾ | – | 6 ½ | 14.68 |
| H ½ | 4 | 7 | – | 14.88 |
| I | 4 ¼ | – | 7 ¾ | 15.09 |
| I ½ | 4 ½ | 8 | – | 15.29 |
| J | 4 5/8 | – | 9 | 15.39 |
| J ½ | 5 | 9 | – | 15.7 |
| K | 5 1/8 | – | 10 | 15.8 |
| L | 5 ½ | – | 11 ¾ | 16.1 |
| L ½ | 5 7/8 | – | – | 16.41 |
| M | 6 | 12 | 12 ¾ | 16.51 |
| M ½ | 6 ¼ | – | – | 16.71 |
| N | 6 ½ | 13 | 14 | 16.92 |
| N ½ | 6 ¾ | – | – | 17.12 |
| O | 7 | 14 | 15 ¼ | 17.32 |
| O ½ | 7 ¼ | – | – | 17.53 |
| P | 7 ½ | 15 | 16 ½ | 17.73 |
| P ½ | 7 ¾ | – | – | 17.93 |
| Q | 8 | 16 | 17 ¾ | 18.13 |
| Q ½ | 8 ¼ | – | – | 18.34 |
| R | 8 5/8 | – | 19 | 18.64 |
| R ½ | 8 7/8 | – | – | 18.85 |
| S | 9 1/8 | – | 20 ¼ | 19.05 |
| S ½ | 9 3/8 | – | – | 19.25 |
| T | 9 5/8 | – | 21 ½ | 19.46 |
| T ½ | 10 | 20 | – | 19.76 |
| U | 10 ¼ | 21 | 22 ¾ | 19.96 |
| U ½ | 10 ½ | 22 | – | 20.17 |
| V | 10 5/8 | – | 23 ¾ | 20.27 |
| V ½ | 11 | 23 | – | 20.57 |
| W | 11 1/8 | – | 25 | 20.67 |
| W ½ | 11 3/8 | – | – | 20.88 |
| X | 11 5/8 | – | 26 ¼ | 21.08 |
| X ½ | 11 7/8 | – | – | 21.28 |
| Y | 12 | 25 | 27 ½ | 21.39 |
| Y ½ | 12 ¼ | – | – | 21.59 |
| Z | 12 ½ | 26 | 28 ¾ | 21.79 |
| Z ½ | 12 ¾ | – | – | 22 |
