Hook Conversion Tool
| Metric | USA | UK | Japan |
| 0.60mm | 14 steel | 6 | 10 |
| 0.70mm | 12 steel | 5 | 6 |
| 0.75mm | 13 steel | 8 | |
| 0.80mm | 11 steel | ||
| 1.00mm | 10 steel | 4 | 4 |
| 1.25mm | 8 steel | 3 | |
| 1.50mm | 7 steel | 2.5 | |
| 1.75mm | 5 steel | 2 | |
| 2.00mm | 0 | 14 | 2 |
| 2.25mm | B/1 | 13 | 3/0 |
| 2.50mm | C/2 | ||
| 2.75mm | C/2 | 5/0 | |
| 3.00mm | D/3 | 11 | |
| 3.25mm | D/3 | 10 | |
| 3.50mm | E/4 | 9 | 6/0 |
| 3.75mm | F/5 | ||
| 4.00mm | G/6 | 8 | 7/0 |
| 4.25mm | G/6 | ||
| 4.50mm | 7 | 7 | 7.5/0 |
| 5.00mm | H/8 | 6 | 8/0 |
| 5.50mm | I/9 | 5 | |
| 6.00mm | J/10 | 4 | 10/0 |
| 6.50mm | K/10.5 | 3 | |
| 7.00mm | 2 | Jumbo 7 | |
| 8.00mm | L/11 | 0 | Jumbo 8 |
| 9.00mm | M/13 | 00 | Jumbo 9 |
| 10.00mm | N/15 | 000 | Jumbo 10 |
| 15.00mm | P/16 | Jumbo 15 | |
| 16.00mm | Q | ||
| 19.00mm | S | Jumbo 20 |
