Storm Dwarf Calvin was a very professional quasi-legendary blacksmith. In his smithy, there were not only all the tools and facilities for forging weapons, but also a Rune Furnace for Death Knights to use.
Actually, the Rune Forging skill of Death Knights and the various enchantments mages cast on weapons are essentially the same thing. Rune Forging can be regarded as a special enchantment that can only use Negative Energy and has a somewhat limited range, with some weapon binding effects.
Every Death Knight must personally forge runes onto their own weapons. They would use the Soul Fire to manipulate the various powers derived from Negative Energy within their bodies, carefully engraving one rune after another on the weapon. As a result, the Death Knight's own Soul Fire would have the same frequency of fluctuations as the unique runes on the weapon, making it feel familiar and one with the weapon when using it.
