DecadentLinuxUserNumeroUno wrote, on Mon, 09 Feb 2015 13:02:42 +0000:

You mean a philips screwdriver shank?

Get a number three. Some of them are square shank, even more "precise".
And they are certainly bigger.

Yes. Sorry. Shank.

Actually, truth be admitted, the first two sections were perfectly aligned,
but, the next two "curved" a bit, due to the difficulties of getting every
board lined up straight while being hung from the cables, so, at times,
it's a screwdriver shank on the right side, but an inch (or so) on the left.

Looking up from below, you can see that these third and fourth 16-foot
sections have a larger board-to-board spacing on the right than on the left:
https://c1.staticflickr.com/9/8632/1...60268c0b_c.jpg