Dark iron ingot is a crafting component in The Witcher 3: Wild Hunt that can be dismantled into dark iron ore. It is needed to craft the following items:
Crafting Requirements 
It can be found as random loot or purchased from the following merchants:
- All armorers and blacksmiths
- Armors and weapons merchants in Nilfgaardian Army Group 'Center' Camp
- Merchant in the boatyard south of Refugees' Camp
- Merchant at Calveit Watchtower
- Merchant at Coast of Wrecks
- Merchant in Ursten
- Merchant by the road west of White Eagle Fort
- Merchant at the sawmill northeast of Rannvaig
- Merchant at the Isolated Hut on Hindarsfjall
- Merchant in Mohrin Village
- Merchant in Stacheier
- Ofieri merchant at Upper Mill
Dark iron ingots can also be obtained by dismantling:
- Dark iron plate
- Dark steel ingot
- Lyrian hardened leather trousers (crafted)
- Feline armor
- Enhanced Feline armor
- Legendary Feline armor
- Enhanced legendary Feline armor
- Ursine armor
- Legendary Ursine armor
- Toussaint Color Guardsman's armor (magic)
- Toussaint Color Guardsman's armor (master)
- Toussaint Ducal Guardsman's armor (master)
- Toussaint knight's armor
- Toussaint knight's trousers (magic)
- Toussaint knight's trousers (master)
- Toussaint knight's tourney trousers (magic)
- Toussaint knight's tourney trousers (master)