DoN. Nichols wrote:

Go for the bearing mount version -- which is also red, IIRC. It
will set up better in threads which may be as loose as these 1.25x7
threads may be.

Yeah, I was kind of surprised how loose the threads were, but everything is
in spec so I guess that's just the way it is with larger fasteners. I think
I'll drop them a line and see what they say about it, thanks for the
suggestion.

But an alternative would be a cross hole with a dowel pin in it
to keep the nut from turning on the thread.

Someone else suggested this, but I don't want to weaken the assembly any
more than I can get away with.

Is that thread an Acme thread? I would consider that better
than a normal V thread for the task.

I couldn't get any tensile strength ratings on ACME threaded fasteners, and
the cost was quite a bit more. If I was going to push this assembly to
anything approaching load limits I would reconsider, but for now It'll be
UNC.

Thanks,

Jon