Dear Patty, Seems like some manufacturers
(or maybe just me) are confused about what size needle is a U.S. 1. I have always knit my socks on two Addi Turbo circular needles, size 1. Sixty stitches usually worked. I wanted to try Magic Loop and bought size 1 Knit Pro needles. Someone at the weaving guild commented that my socks looked a bit small. Sure enough, no way was I going to get those puppies over my heel. The needles were 2.25 mm as opposed to Addi's 2.5 mm. Made a big difference on the socks. So what's the deal?

—Tiny Sock Knitter   

Dear Tiny Sock Victim, Oh dear, I feel your pain. It reminds me of my old yarn store days when I was managing a shop in the West Village (now closed), and a tourist from Canada came in. She had been swatching for a chunky hat and was trying her best to fit in and to deal with our crazy needle system. She politely asked to buy a U.S. 12. I told her there was no such thing; we had a U.S. 10, 10.5, 11, and 13. She asked why and I said "it's because, um, you see… how our needles work is, um… the sizes are… (pause) I have no idea."