A 3.5mm crochet hook is a US E-4, and UK size 9. I use this size most for DK weight yarn projects where I want a tighter, more structured fabric than a 4mm hook would give.
What is a 3.5mm crochet hook used for?
This size pairs well with DK and light worsted yarn, and it’s a common choice for amigurumi where a tight stitch keeps stuffing from showing through the fabric.
- Yarn weight: DK to light worsted.
- Common projects: amigurumi, tighter-gauge garments, baby items.
How 3.5mm compares to nearby sizes
Dropping to a 3.5mm from a 4mm hook noticeably tightens the fabric in the same yarn, which I do deliberately for toys that need to hold stuffing without gaps. Going up to 4.5mm instead opens the fabric up again for a softer, more flexible result.
Frequently asked questions
What letter is a 3.5mm crochet hook?
A 3.5mm hook is a US E-4. In UK and Canadian sizing, the same hook is a 9.
Is 3.5mm good for amigurumi?
Yes, many amigurumi patterns call for a hook one size smaller than the yarn label suggests, which often lands right at 3.5mm for DK weight, to keep stitches tight enough to hide stuffing. I use this trick on almost every toy I make.
What yarn weight uses a 3.5mm hook?
DK weight is the most common match, though light worsted also works for a slightly looser result.
See the full hook size chart
Compare 3.5mm against every other mm, US, and UK size in one table.