Hex Coupling Nuts as bushings?

A friend of mine, who's recently also caught the RepRap bug, was looking for bushings to use with the 8mm rod. With access to a lathe, he reamed out some Hex Coupling Nuts, using an 8mm reamer, and gave me some to try. The process was quick and the result was excellent!

With 8mm centre removed what's interesting is that a sliver of thread groove remains inside. We figure this would serve well to retain some light lubricant.

It's a lovely fit and a very smooth movement.

I've fitted a pair to my X-Axis just 'cause! I'm begining to think the extruder platform might actually be stable enough with only two of these... they are such a good fit!