I just wanted to share something... I have tried the square cross section needles and except for very bad quality finish (check thoroughly on all sides before buying) I do love them. I had to return all five sizes and ask for selected needles.
The size marks will come off after a while but the diagonal of the cross section is supposed to be the size corresponding to a circular cross section, but that will give a shorter circumference which may be the reason for those who have tried them to experience a tighter knit. Look here:
The equation for the side length is simple: 3.1415*(nominal size needle)/4 which should have been the side length, the actual circumference of the square cross section is (nominal size needle)*cos(45)*4 which for a circular cross section would have been 3.1415*(nominal size needle).
The Cubics needles feel more flexible too and the reason for this is the bending stiffness of the square cross section needles is only 60% of the circulars:
Wcircular=3.1415*(nominal size needle)^3/32=0.0982*(nominal size needle)
Wsquare=((nominal size needle)*cos45)^3/6=0.0589*(nominal size needle)
Which means the material utilization gets better and therefore the price should have been lower... about 36% less. (1-3.1415/4/cos(45)^2)=0.36.
Was this clear to you? *lol*! Did I mention I'm an engineer :-)?! So, tell me how did they come up with the name Cubics? the cross section is square (2 dimensions or 2D) and a cube has the same length in all three directions (3 dimensions or 3D)... So it must be a bar with a filled square cross section with conical edges...BarConics maybe...?