Steel line is a crafting component in The Witcher 3: Wild Hunt. It is not needed to craft anything but can be dismantled into steel ingot.
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