On 5/18/2013 5:22 PM, Gerry wrote:
...It will be used for cleaning up existing threads, ...

If there is not much cleaning to be done, if the threads don't need to
be real pretty, and if you have a 9/16-28 nut, you can use the nut to
clean them up by using a hacksaw blade to put a few teeth on the nut's
threads. But then, who has a 9/16-28 nut?

Bob