How does the lettering and numbering go with crochet hooks?

This is very complicated. The US uses a different system than the rest of the world. And if you have some old UK hooks, they are different as well. The only reliable sizing is metric. They measure the diameter of the hook. That is more accurate than anything else.


http://www.purplekittyyarns.com/info/cro鈥?/a>


http://www.yarnforward.com/crochetconv.h鈥?/a>


http://www.vintage-crafts-patterns-desig鈥?/a>


Here's the bottom line: use a crochet hook which matches the size of the thread you are using.