Looks like you welded a threaded rod to the tang then drilled it straight through to the end of the handle and put a nut on there. I believe that's what they call a rat tail tang. I just did my first one like that for my brother for a Christmas present.
I've seen you post that you use tru-oil on your handles. Do you have a link for the kind you use, I've never seen it before. I usually use boiled linseed oil....thanks.