3.5 mm knitting needles are the smallest size needles available in most sets of knitting or crochet. This size is often used for smaller sized projects such as hats and slippers, but they can also be used for scarves, shawls, or baby blankets.
The small size of 3.5 mm needles provides you with the ability to easily maneuver them into multiple areas on multiple pieces of fabric at once without being long enough to poke through your work. The thin needles make them easier to manipulate in a crowded area. The small size also makes it easier for small people to use the project as they are able to hold the needle in their tiny hands and maneuver the needles themselves.
The size of 3.5 mm knitting needles is used by some knitters and crocheters when making items for children, or when they want a smaller sized project for personal use, such as socks or hats.
In knitting, the 3.5 mm size is used for projects such as hats, baby booties, sweaters, mittens, slippers and scarves. Crocheters use 3.5 mm crochet hook to crochet hats, scarves and gloves.
Knitting Needle / Crochet Hook Size Conversion Chart:
| mm | UK | US | crochet |
|---|---|---|---|
| 2.0 mm | 14 | 0 | |
| 2.25 mm | 13 | 1 | B |
| 2.5 mm | 12 | – | |
| 2.75 mm | 12 | 2 | C |
| 3.0 mm | 11 | 3 | |
| 3.25 mm | 10 | 3 | D |
| 3.5 mm | 9 | 4 | E |
| 3.75 mm | 9 | 5 | F |
| 4.0 mm | 8 | 6 | G |
| 4.5 mm | 7 | 7 | |
| 5.0 mm | 6 | 8 | H |
| 5.5 mm | 5 | 9 | I |
| 6.0 mm | 4 | 10 | J |
| 6.5 mm | 3 | 10 1/2 | K |
| 7.0 mm | 2 | – | |
| 7.5 mm | 1 | – | |
| 8.0 mm | 0 | 11 | L |
| 9.0 mm | 00 | 13 | |
| 10.0 mm | 000 | 15 | |
| 12.0 mm | 17 | ||
| 15.0 mm | 19 | ||
| 20.0 mm | 35 | ||
| 50.0 mm | 50 |