Super Fine yarn (CYC 1)
The short answer
This yarn is called Super Fine in the US and 4 ply in the UK, aiboso in Japan. Use a hook between 2.25 mm and 3.5 mm with it.
CYC weight 1 — Super Fine in the US, 4 ply in the UK, aiboso (合細) in Japan. Socks, lightweight shawls, fine amigurumi.
| CYC number | 1 |
|---|---|
| US | Super Fine, Fingering, Sock, Baby |
| UK | 4 ply |
| Australia | 4 ply |
| Japan | 合細 (aiboso, "fine, plied") unverified |
| Wraps per inch | 14-30 |
| Hook range | 2.25–3.5 mm |
| Single crochet gauge | 21-32 sts / 4 in |
On Japanese yarn
Japanese yarn is normally sold by ball weight with a stated metres-per-gram rather than by a
weight category. The names above are conventional descriptions, not a standard. When substituting,
match metres per gram, not the category name.
Hooks for this weight
Super Fine yarn
Acrylic, cotton and wool options at this weight.
View on Amazon USShopping elsewhere? Amazon UAE
As an Amazon Associate we earn from qualifying purchases. Links to Amazon on this page are affiliate links; buying through them costs you nothing extra.
Other weights
Last updated 2026-08-30.