Borderlands 4 Frank the Furnace Location, Route and Loot Drops

What to know

• Frank the Furnace is a member of the Foundry Freaks boss trio, found inside The Pitted Stain drill site in the Fadefields.
• The Pitted Stain is reached by progressing through Idolator’s Noose in the Fadefields.
• The arena features hazardous machinery, many mobs, and close-quarters combat—gear up with non-fire elemental weapons for best results.
• Frank specifically drops the Chaumurky legendary grenade, while his partners Hank and Sal drop other legendaries.

Hunting Frank the Furnace in Borderlands 4 adds a hefty challenge and packs a loot punch. As players venture through the Fadefields, this infamous boss arena becomes a rewarding farm location, with each boss offering unique legendary weapons and lots of chaos for those prepared to face it.

How to reach Frank the Furnace

Frank the Furnace is found in the dedicated Ripper Drill Site called The Pitted Stain, deep within the Fadefields region. Here's how to find it:

Step 1

After travelling to Idolator’s Noose, follow the quest path or manual exploration to reach the large door at The Pitted Stain drill site.

Step 2

Enter the arena and clear out the waves of Ripper mobs that spawn before triggering the Foundry Freaks boss encounter.

This spot is considered one of Borderlands 4’s best loot farms, with a high concentration of mobs for XP and legendary item drops. Each member of the trio—Frank, Hank, and Sal—has their distinct loot table.

Step 3

Once all mobs are cleared, Frank the Furnace, along with his partners, will drop into the arena for the boss fight.

Step 4

Defeat Frank the Furnace, Hank the Welder, and Sal the Engineer to claim their legendary loot. Frank drops the Chaumurky legendary grenade.

Boss behavior and fight strategy

Frank the Furnace specializes in strong furnace and flamethrower-based attacks covering wide areas. Watch out for periodic sweeping ground flames and hazardous erupting panels on the floor.

• Ideal counter elements include Shock or Cryo (avoid using fire weapons).
• Keep distance, use cover, and leverage ranged or splash-damage weapons.
• The fight is intense, with multiple hazards—ensure your build and shield are up to the challenge for efficient farming.

Item drops and loot table

Tracking down Frank the Furnace leads to one of Borderlands 4's top-tier boss arenas, both for action and loot. Entering The Pitted Stain and surviving the Foundry Freaks is a rite of passage for legendary hunters—just remember, preparation is key.