HI uses a stick tang - there's a long stick of soft metal that goes through the whole handle. The handle goes completely around the tang.
The chiruwa style knives have a flat tang, with pieces of handle (wood or horn) on each side - looks like a good kitchen knife.
On a very few HI knives and some villagers there is a partial tang - the metal doesn't go through all the way, maybe 2-3 inches into the handle.
I suspect antiques used all three styles, depending on the material.