Bring 4 Fel Iron Bars, 2 Arcane Dust and 4 Motes of Fire to Rohok at Thrallmar in Hellfire Peninsula.
Fel orc blacksmiths may not be the most skilled in the world, but there is some craftsmanship to their trade. Only fel iron can be used with this mold if we want to end up with a working key - anything else would probably end up breaking it.
Bring me some fel iron bars, a bit of arcane dust and motes of fire. I'll try my hand at it, but I make no promises.