I have a mindless knitting scarf on size 10 needles that i work on in class or watching t.v. etc. But since i take it everywhere, i’m always loseing the loose needle. I went to look for a substitute and discovered that size 10s are supposed to be 6 mm but my size 10s were 5.75 mm. Whats up with that? Is it the brand? (They’re Boye brand) Will it make a difference if i knit with one 5.75 mm needle and one 6 mm needle?
I have confusion…
It’s a brand thing. I know some Addi’s are a little different.
If .25 mm makes a difference in a scarf on size 10 needles, then this is too fine a science for me!
US non mm sizes (especially older needles, bought at thrift stores, or from family) HAVE NO INDEPENDANT STANDARD.
Boye was for YEARS a US standard (ie when the goverment in a contract stated a gauge, they stated the gauge as per BOYE needles) but there was no real standard.
anyone could call any meaurement size 10!
MM sizing is more accurate. so a size 10/6mm is (or should be!) 6mm.
but older size 10s? they can be any measurement the company wanted and every company had a different idea of what size 10 was, (and made there own needle gauges… (vintage patterns often state “Size 6 Zepher® brand needles” (or size required to get gauge) and Zepher® brand size 6 might be bigger (or smaller) than Boye brand, or Susan Bates or other brands!
in the old day (say 1950!) there were big difference between brand X and brand Y size 10’s!
you only have to find some old gauges, (different brands of gauges!) and try out needles to see, (quickly!) that not all sizes are equal.
the older your needles, the more likely they are NOT TO BE CONVERTABLE to a MM size!
This sometime can cause gauge problems…
if a designer has a favorite needle (say the all nylon ones!) and uses them to knit something, it might not be possible (readily!) to get the same gauge on a new needle… that .25 mm is enough to through off the gauge!
I have needles from the 1950’s… and while they are close in size to modern sizes, they are off…
(you can in an art/architect store (in NYC Charette comes to mind) find micronmeters (tools to measure gaps or diameters) --about $10 and check out all you needles–and see what size they really are! if you have an engineer in the family, you might be able to borrow the tool (or get them to size all your needles.)
It probably won’t make a difference, to knit with different sizes, but since you have to get new needles, just do the knitting on them. Or think about getting a circular needle and you won’t lose just one of them. 
Sue I was thinking that too… Hey get circulars… then you can’t loose one…
Wow, thanks of troy. Thats actually really interesting. Now i know to actually check my needle sizes. It just seems so odd to me that they don’t have a standard. It probably won’t make much diffrence on my scarf if i use two different size 10s but i can imagine that a .25 mm size difference would be noticable in other work.
And i didn’t think about circulars 
that’s a good idea. See, i lack logic sometimes…
I have some needles about 30 years old and some are just a skosh larger than the new ones, according to my needle gauge, but most are the same as the newer ones.
This is the most comprehensive needle chart I’ve come across, and it’s as of Troy says, some of it based on Boye needles.
I don’t think it will affect your gauge.
I bought a set of needles. Started knitting with them, got about halfway into the project and realized I had one 8 and one 10 in the package… instead of 2 sized 10’s. It didn’t affect my gauge at all.
~Sunny
Re:[COLOR=Blue]I bought a set of needles. Started knitting with them, got about halfway into the project and realized I had one 8 and one 10 in the package… instead of 2 sized 10’s. It didn’t affect my gauge at all.[/COLOR]
it might have been luck! many people purl at a different gauge than they knit (it’s called “knitting out”–if it is noticable) and if you used the smaller needles for the purls, and the larger for the knits, it might have worked out fine! it would have tended to even out your stitches.
the difference between knit gauge and purl gauge might not always noticable, but switch from knitting in the round(no purls) to flat knitting (half the row purled in stocking knit) , and it becomes very evident!–even many experienced knitters have a problem!
but i don’t knit and purl at different gauges–(i used to, but eventually i learned to knit better(i have been knittting 45 +years!))
and
[B]1–[/B]i would have noticed the differnt sizes (of needles) right off the bat.(again, just time and practice!)
[B]2–[/B]it would have effected my gauge.-noticeably!
[B]3–[/B]if you had bad luck & the worked it so the Knit stitch was on the smaller needle and the purl on the larger, it might have been ( & if you are like 90% or so of knitters!) VERY evident.
and while Boye’s haven’t changed much, there is still a big difference between say Boye (new or old) and Lion Brand Needles!
(buy a Lion brand gauge and compare!)
and there are many other brands (the further back in time you go, the more brands needle there were!–(and i mean just to 1950!–and i have some 1950’s needles in my collections… (my first needles were bought in the 1950’s (OK so it was 1959…but…)
There are US ‘standards sizes’ (for clothing) but manufactures are NOT REQUIRED TO USE THEM. so Brand A’s size misses 8 can be very different than Brand X’s --(and there tend to be price relationship… in walmart clothing, you might be a size 10…but upgrade to shopping Saks 5th Avenue, and you might find you are only a size 8, or maybe even a size 6! sure the skirt cost 4 times as much, but OH,to be a size 6! it’s worth the money for how you feel!)
the same is true for needles… the various brands are similar… but there are differences! (and before [B]mm sizing[/B], the difference were much greater!) With MM sizing, a size 5mm needle should be 5mm. (and not 4.75 mm!)
–but a 5mm needle might be, 5.03, or 5.08 or 4.97, or 4.92mm–close enough…
but the best brands aren’t 5.03mm, they are 5mm almost exactly (maybe 5.001 or 4.009!)
Now this has gotten me all curious so i “borrowed” my dad’s micronmeter and measured all (that i could find) of my needles. Most of them were slightly off of their marked mm size, though not enough to effect gauge probably. All of my Clover bamboo needles were exactly the right size though, so yay for them making a good product.
True fact. haha I’m working on a project right now and I have a size six needle for knitting and a size 5 for purling to help even things out