Will the real size 10 please stand up?
At my local thrift store tonight, I found a set of knitting needles. (I might post a pic tomorrow, when I get them off my phone, if that's okay with the mods. It was a fairly sweet find.) I was very happy! But after I got them home, I got a better look, and discovered that I had two sets of size tens. One is 5.75mm, and one is 6mm. Can anyone explain this to me, please? And if they're both correct, which one is the more commonly used one?