I've already known this. I wouldn't be asking about the Weapons if I didn't know how to make them. You can temper ALL the Nord Hero weapons EXCEPT the Bow.
The problem here is that the Tempering recipe for the Bow has the wrong item (the Battleaxe) in the output box, so doesn't work. The 'Supple' and 'Honed' Ancient Nord items, on the other hand, don't even
have tempering recipes in the first place. Both of these issues are fixed in various mods, however that's not of much use for those on console systems so it would be nice if Bethesda fixed it as well.
There are a few other items that have no Tempering recipe, among which are the Honed Falmer weapons.