George, please forgive me for completely omitting this fine point. I learned a lesson just now for amking assumptions.

What it is:
The s/s t-nuts are a lighter weight alternative to the expensive and heavy s/s threaded insert. As a background, the t-nut looks somewhat like a "t" when looked at sideways, from the top it's a cicular flange with a protruding central sharft that is threaded. The intent is to provide a s/s threaded hole in a surface with the flange hidden under the surface, like a deck. The t-nut is useful for providing a mounting point for a deck line loop, for mounting padeyes, for mounting a fixture that needs to be screwed down, etc. Please see the attached link for what these things I go on incessantly about actually look like (hey, everybody likes something, my thing is t-nuts. I know it's weird and someday I'll get some help on it! )

Typical installation:
Drill a hole the size of the threaded barrel part, mix up some epoxy, paint the hole, then from the underside (the hidden side), push the threaded barrel part up through the hole, then either tap in place, or like I like doing, thread a bolt of the right thread into the barrel from the top and pull it up by tightening against the appropriate sized fender washer. This will draw the flange tight against the undersurface-let's say a deck-leaving a nicely threaded hole. It's a convent way to install mounting points and leave a professional, workmanlike appearance.

Please forgive me for the delay in replying, I did the same with a few other E-mails and can only say I didn't scan down the list in the inbox carefully. It's sadly an age thing with me.

Hope this helps, let me know if you need some images of applications on a kayak which I can send to you.

: I've been following your build journal with interest; but I wonder if you can
: expand on what, exactly, you're using the SS t nuts for.