Cubics, huh, what are they good for?

I got an early Christmas present this weekend, a full set of Knit Pro Cubics! I’ve been hearing about these square needles for a while, and finally I have a chance to try them out! Some of the good things that people have been saying about them is that they can be less stressful on the hands and wrists, and that they can fix tension problems such as rowing out (where you knit and purl stitches are slightly different sizes, creating inconsistencies in stockinet).

Cubics interchangeables

The set itself is a wooden tipped interchangeable set. The tips range from 4mm (unlike their other sets that start at 3.5) to 8mm, a total of seven pairs. There are also four cables, 60cm, two 80cm and a 100cm, plus the usual end caps and cable keys. The cables are black, rather than the usual Knit Pro magenta.

So the first question is, what does 4mm actually mean for a square needle? When we talk about a 4mm needle usually, we’re referring to the diameter, but the important measurement is the circumference, which is 2*pi*r where r is the radius, or pi*d where d is the diameter. According to the cubics, 4mm refers to the diagonal of the cross section, so each side of the square of a 4mm needle will be 2*sqrt(2) in length. So the total distance around the needle is 2*sqrt(2)*4.

So in actual numbers, this amounts to 12.6mm for the round needles, and 11.31mm for the square. The 3.5mm round needle has a circumference of ~10.99mm, so a 4mm square needle is closer to a 3.5mm round needle. On the other hand, the square 4.5mm needle has a distance of 12.72mm, so 4.5mm square is closest to 4mm round.

(Of course, this all operates on the assumption that the yarn hugs exactly to the contour of the needles. Probably fine for laceweight, but  probably a less fair assumption for thicker yarns or stiffer fibres, like cotton.)

Cubics close up

So this has two main upshots.

First, you’re going to have to swatch. This is probably a good thing, at least for me, because I do need an incentive to do that work. I haven’t been caught out yet, but it’s only a matter of time. If I have to swatch because I can’t just expect my needles to be right, then that’s got to be a good thing.

The second thing is that it gives you more options for getting gauge. Sometimes I’ve found that the listed needle size isn’t right, but one up or one down takes me too far to the other side of the gauge. Now if my round 3.5mm are too small, and my round 4mm are too large, I can try the square 4mm and hopefully find that sweet spot.

In order to experiment, I want to take some left overs from Catriona, and try knitting up on round needles and square needles. The two things I want to look at were gauge and tension. I also want to try things like cables and decreases to see how they’re affected. So much fun to be had!

Unfortunately, with work commitments, and nanowrimo, I’ll have to save that for another day. One thing I have noticed though, knitting with cotton on the cubics is much less hard work. I think this is because the cotton is so stiff, it doesn’t hug the square like wool does, so you get bigger stitches on smaller needles. So my gauge will be larger but the stitches slip and slide around with no problems.

Cubics knitting up cotton

One final comment, how to check needle size? When the printed sizes wear off the tips, as they will if the other needles I have are anything to go by, can I still tell which tip is which? In theory a needle gauge designed for round needles will still work, since the measurement is on the diagonal. In practice, I did find my 4mm squares didn’t quite fit through the 4mm hole. It was marginal, but something to bare in mind. On the other hand, if you’re knitting to gauge rather than needle size, then the exact numbers are less important.


I’ve been a terror on my WIP schedule recently. I’d love to blame nanowrimo, but it kinda happened before then. I did cast on a new thing a couple of weeks ago, and I have these new needles to put through their paces. Currently I should have

Monday: Shawl 7.0

Tuesday: Sparkley socks

Wednesday/Thursday: The big silk shawl of doom’s border, and the newly cast on green sparkly shawl.

Friday: Shawl 3.0.

So out of my 15 initial WIPs, I’ve finished four, frogged two, and cast on one, leaving me with 10 projects, half of which are hibernating. Not too bad, I think. I’m looking forward to seeing how Ardara comes along.

2 thoughts on “Cubics, huh, what are they good for?

  1. For me it works that it’s the smallest hole it will fit into (but it’s almost always very snug). Though now you’ve made me paranoid! I will have to test this theory tonight.

  2. You are such a lucky lady! The cubics sound amazing: less RSI, better for purl/knit differences AND better for stiff yarns/fabrics – what more could a girl want?! If the 4mm doesn’t quite fit in the gauge hole then that’s perfect too. Isn’t the size the largest hole that it doesn’t fit in? That’s certainly how all my needles work in the gauge. All equipment must be calibrated :)