Did you know that not all crochet hooks in the same letter size are the same mm size? For example, Boye and Bates measure differently. I did know that but didn't pay much attention to it until I needed a Bates hook to work with a particular yarn that didn't like the Boye hook. It split less with a Bates style.
Annie's Attic has a nice list which includes all sizes but doesn't say what type of hook it is. I used to have this info at Crochet Cabana but have since removed much of the extraneous info from the site since it is readily available all over the Internet.
Crochet.com also has info on hooks. They list hook sizes but don't designate.what style is what sizze.
Here are the sizes and a picture for reference.
(I added a few that are not in the pictured set)
L 8.0mm
Of course you can find the Bates and Boye style hooks lots of places that are not specifically made by Boye or Bates. They are identified by the style - inline (Bates) or tapered (Boye)
I hope this helps you. This is why I suggest you use the same hook when working a project. If you happen to change to a different hook with the same letter sizee it might not be the same mm size. Depending on what you're making it may make a difference.
In addition to the sizes that are made today, it seems like the hook mms changed slightly through the years. There's an interesting article about Boye hooks here if you want to delve more into that.
Happy crocheting!
Sandie
