My knitting pattern calls for US 6 knitting needles. I wanted to add a little i-cord to the end and went to grab my DPNs in the same size but they don’t have US sizes on them. I looked at the end of my straight needles and it says “4.25 mm” but I didn’t have 4.25 mm DPNs. They are 4.0 mm. So I checked my circular needles and they say 4.0 mm which is strange because my straight and circular are made by the same company. Then, I searched for a needle chart and 4.25 mm aren’t even listed. I know I’m getting old but they clearly say 4.25 mm. Any ideas as to why there is a discrepancy?
I have found that the US size 6 really is two different mm sized. No idea why one company would make two different sizes of 6 though. My Loopy Ewe needle gauge lists both the 4.00 and 4.25 as a US 6
I’ve seen a US 6 listed as both a 4.25 mm and a 4 mm and even as a 4.5 mm on one chart that I just didn’t trust at all! The weird thing is that you’ve got two different measurements for a 6 from the same company. I would just go by your gauge and not worry about the measurement on the needles. I knit very tightly so I almost always have to go up a needle size or two from the size recommended in the pattern to get the right gauge. If you get gauge with the 4.25 mm needles, use those. WIth an I-cord, it’s not going to matter too much if you use the exact same size needles as you did for the rest of the pattern. When I make an I-cord as a drawstring or an accent, I usually go down a size or two from the size recommended on the yarn’s label so it is a nice, tight weave and not too stretchy, but that’s just me.