I am almost done building the base of a shaker style workbench (reduced
scale, of course).

As I am new to ww, I attempted T&M but find the joints a bit too loose. Plan
to pin the tongues, but still would like to run all thread at least
lengthwise to help keep the joints tight. It may be overkill but I do not
want to go back later and fix.

Anyone have suggestions on how thick a diameter the all thread should be? I
would prefer the smallest diameter. Tongues are 3/4 inch thick, with 1/4'
shoulders.

Thanks for the advice...