The tribes of Orcs are collecting a vast amount of metal resources from the Redhorn Lodes. Their forges burn day and night, and they must have Orcs processing that metal into armour and weapons.
You notice larger Orcs are tending the forges, and must be wicked metal-workers of the enemy.
The tribes of Orc have forges at the hearts of their camps, out among the ruins in the main cavern of the Redhorn Lodes.
The fiercest Orcs tend the forges, to process their collected metals, and fashion armour and weapons for the rest of the rabble.
You have defeated the Moria and White Hand Metal-workers.