A suggestion for those doing welded on tangs.
Make your tang stub and shoulders after the bevels are shaped. There is no need to cut them out ahead of time. Draw them in with a Sharpie if you want, but they should be almost the last thing ground away. That will lessen the sharp corners and often too narrow tang. Weld the tang extension on, and then grind the metal back to form the tang. This gives you an even weld line, without burnouts.
The tang is best shaped with the first 3/8" to 1/2" being just about 1/4" narrower than the blade width at the ricasso.This makes for a good wide guard seat. Then drop back with a curved step, and for the next 1" the tang should be 1/2 the ricasso width. After that the tang can be just threaded rod, or mild steel bar. You really need 1.50" of tang in the blade stock before the stub ends and the rod starts.
While the weld can be made anytime, it is often easier to weld the tang extension on before any shaping of the blade. The best way to add a threaded rod is to cut a 1/2" long slot the width of the rod, set the rod in the slot, and weld up both sides. Then you just grind down the rod thickness to match the tang thickness. This gives a flat tang rod with threaded edges. 1/4" threaded rod works best. If it is a bit sloppy in the slot, just hammer it to spread it to a flush fit before welding it up.