Use this quick reference when reading a pattern, then confirm the millimetre diameter on the tool. The chart is an original, limited compilation of commonly encountered labels.
Enter the physical diameter. Exact common matches appear in the result; the complete reference remains below.
10 mm
| Millimetres | US label |
|---|---|
| 2.25 mm | B-1 |
| 2.75 mm | C-2 |
| 3.25 mm | D-3 |
| 3.5 mm | E-4 |
| 3.75 mm | F-5 |
| 4 mm | G-6 |
| 4.5 mm | 7 |
| 5 mm | H-8 |
| 5.5 mm | I-9 |
| 6 mm | J-10 |
| 6.5 mm | K-10½ |
| 8 mm | L-11 |
| 9 mm | M/N-13 |
| 10 mm | N/P-15 |
Read the chart without over-reading it
Find the millimetre row first, then use the US label to interpret pattern notation. Combined or missing labels reflect variation in naming rather than a missing physical size.
A chart cannot identify an unmarked hook by appearance. Use a physical sizing gauge or measure the shaft, and never infer diameter from colour or branding.
How to use this page
- Find the millimetre diameter first.
- Use the US label only as a pattern-reading aid.
- Print the page if you need an offline bench reference.
What to check before you rely on the result
- Not every brand makes every size.
- Labels at uncommon diameters may differ.
Source note
This original presentation was checked against the relevant Craft Yarn Council reference. Regional labels may vary; no third-party graphic or table layout is reproduced.
Consulted authority ↗