On 2010-05-21, GeoLane at PTD dot NET GeoLane wrote:
Maybe I didn't use the right words at McMaster-Carr, but I didn't spot
a 5/8-20 nut there. I need one for my tool and cutter grinder. I
suppose if I have to I can make one on my lathe, but it would be
easier to buy one if they're available somewhere. Where can you find
odd size nuts?

Try google, they are plentiful.

http://www.google.com/search?q=%225/8-20%22+nut

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