Brian Whatcott wrote:

Annealed 316 wire yields at a pressure of 34,800 lb.
[see Matweb]

The cross section area of a 1/4 in X 20 tpi screw is about
pi X r X r square inches where r is the effective radius.
Using r = 0.06 inch gives a = 0.011 sq in
so the force at yield is about 0.011 X 34800 lb
That's about 390 lb.
The bolt will break before the nut.
You could give a X5 safety factor and take the maximum
unit load as 75 lb each.

You're welcome

Brian Whatcott Altus OK


Brian,

Thanks for walking me through that. Seems straight forward with your
explination.
Now time for me to get back to the boat.

Bob