On Mon, 9 Nov 2009 18:59:02 -0800 (PST),
wrote:

(view in Courier font)
.--.
.
.--. \
. . |
/ \ / b.
| - |//|
|.--' '----'/ .
a. |'--. .----. /
| - |/
\ / /
/. .:
/ ' -- ' :
bore _
|=|
[___] --clamp screw

a = "hinge"
b = "cut"

I've made some homemade flex couplers using setscrews to bite the
shafts, but clamps are sooo much classier.
This crappy drawing is an end view of the clamp portion of a helical
flexible beam coupler. Question: how's that cut made, from b. to a.?


Slitting saw. If you were to look at a section thru the cut you'd see
a radius equal to that of the saw adjacent to "a" in your drawing.

--
Ned Simmons