What is different
The shaft is a rounded square instead of a cylinder: four soft faces and four soft edges, with the usual round, tapered tip at the end. The stitch sits on the needle exactly as it does on a round one — the loop does not care — but the fingers do. There is a face to rest the thumb on and an edge to register against, so the hand holds the needle with less squeeze. addi's version is the Rocket2 Squared: the Rockets' sharp lace tip and plated finish on the square shaft.
The claims, and what holds up
Less hand strain. The best-supported one. A square shaft is held rather than gripped, and knitters with arthritis, carpal tunnel or simply long sessions report less ache. It is the reason to try one.
More even tension. Plausible and often true. The stitch is formed around a shape with corners, which gives each loop the same size with less help from the hands, and knitters whose stockinette is uneven tend to see it improve. A knitter with even tension already sees nothing.
Faster. No. The square has a little more friction than a round nickel shaft — stitches do not fly as they do on a Turbo — and that is the trade for the control.
Square stitches. No. Once the stitch leaves the needle it is a loop of yarn like any other; blocked fabric from a square needle is indistinguishable from fabric off a round one.
Who should try one
Anyone whose hands hurt after an evening's knitting; tight knitters, who squeeze round needles hardest; knitters whose tension wanders; and anyone who found the Rockets' sharp tip right but the round shaft slippery. Lace and cable knitters get the tip and the control together.
Who will not like it
Fast plain-stockinette knitters who love the Turbo's slide, and knitters who hold the needle very lightly already. The square also feels odd for the first few rows to everyone; give it a hundred stitches before judging.
Sizing
A square needle's size is the diameter of the circle it would make — the same millimeters as a round needle of the same label — so a US 8 Squared knits to the same gauge as a US 8 round, give or take the usual swatch. Some knitters find they need a half size up on a square shaft; the gauge swatch guide settles it in twenty minutes.
What we stock
addi Rocket2 Squared circulars in 24", 32" and 40", from US 1 to US 11 — socks on a 40" magic loop through chunky sweaters. The addi guide puts them beside Turbos, Rockets and FlexiFlips, and the material guide is the other half of the hand-comfort question.