Feed The Beast Wiki
This page is about the Arc Furnace from Immersive Engineering. For other uses, see Arc Furnace.
Arc Furnace
IE Arc Furnace Complete.png

ModImmersive Engineering
TypeMultiblock structure
Previous tier
Max RF input4096×3 RF/t
RF use512–6144 RF/t
RF storage64,000 RF

The Arc Furnace is a 5×5×5 multiblock machine added by Immersive Engineering, used for smelting ores and grits into ingots, creating alloys including steel, and recycling certain tools and armor.

For it to operate, the Arc Furnace needs power and three working Graphite Electrodes. Alloy recipies need additional additives. Most recipes create Slag as a byproduct.


1st frame: An HV capacitor with 2 outputs, each leading to its own plug on the Arc Furnace. 2nd frame: Two HV capacitors, each with 1 output leading to its own plug on the Arc Furnace.

For the machine to be capable of full speed, it needs power through 2–3 connectors.

The Arc Furnace accepts power in the form of Immersive Flux (IF) or any other RF-equivalent system. After slotting in three Graphite Electrodes using the GUI, the Arc Furnace is ready for use. Smelting 12 items at once demands a large amount of power, but it's also easiest on the Graphite Electrodes. The furnace slows down if the power supply can't meet the demand, but energy is not lost.


The Arc Furnace accepts power at three large plugs behind the machine. Most operations cost 51,200 Flux, and smelting ores cost twice that much. Each operation demands up to 512 Flux/tick, and there is no idle cost: Power is only drawn while the machine is smelting.

Power demand scales up linearly with how many items are smelting at once. With 12 simultaneous jobs, the furnace's demand maxes at 6144 Flux/t. If its power supply can't meet the demand, the furnace slows down. Supplying too little power doesn't cost extra energy, but it does strain the Graphite Electrodes for longer. For the furnace to be capable of full speed, there need to be 2–3 connectors on both the machine and whatever's supplying the power.


The furnace needs three Graphite Electrodes before working. While the furnace is smelting, electrodes slowly wear down at a rate of .021%/second (providing 4760 seconds of runtime). This is a flat rate while operating, so taking more time to smelt than needed causes excessive wear on the electrodes. This can be alleviated by providing sufficient power, spreading stacks out, and crushing ores into grits before smelting them.


The Arc Furnace can make ingots directly from ores (which are doubled), or it can do it from grits (which smelt in half the time). Alloy recipes also take additives (Coke Dust for Steel, Gold for Electrum, etc.). As of Immersive Engineering version 0.6.1, the Arc Furnace can also process Ender IO alloys and recycle undamaged metal tools and armor into the ingots used to craft them.

Smelting most metals creates Slag as a biproduct, which quickly builds up in a dedicated slot. Slag build-up can halt the machine if it's not removed.

Input Additive Energy Time Result
Any ore 102,400 Flux 10 s 2 ingots
Any grit 51,200 Flux 5 s 1 ingot
Copper Ingot Nickel Grit 51,200 Flux 5 s Constantan Ingot
Gold Ingot Silver Grit 51,200 Flux 5 s Electrum Ingot
Iron Ingot Coke Dust 51,200 Flux 5 s Steel Ingot


The GUI shows four inventories: 12 slots for input on the left, 4 slots for additives on the top right, 7 slots for outputs at the bottom, and 3 slots for Graphite Electrodes at the top. Each inventory can be accessed from an external hatch on the machine, except for the electrode slots.

The 12-slot inventory represents the body of the furnace, and it accepts grit, ores, ingots, and undamaged tools as input. Each item has a temperature indicator to its right, showing its progress to fully melted. Conveyor Belts (and similar) can only access these slots through the blue hatch above the vat, left of the electrodes.

The 4-slot inventory on the right is for additives: extra items needed to smelt alloys. These are different for each alloy recipe (e.g. Steel needs Coke Dust). Conveyor Belts (and similar) can only access these slots through the blue hatch above the vat, right of the electrodes.

The 7-slot inventory at the bottom is for outputs. 6 of these fill up with ingots, while the 7th slot is dedicated to trapping Slag. Conveyor Belts (and similar) can retrieve ingots through the black 'bucket' port on the front of the furnace, and they can access the slag trap through the orange port at the back.

The 3 slots at the top only accept Graphite Electrodes. Conveyor Belts (and similar) can't handle these electrodes, so once they run out they have to be replaced manually.

The control panel on the front (with a red dot) accepts an active redstone signal to halt the Arc Furnace. If the furnace stops for any reason, its smelting progress pauses.


Once the blocks are assembled, use an Engineer's Hammer on the Cauldron block to finalize the structure.

The completed machine has a GUI and 5 world interfaces:

  1. Power plugs in the back
  2. Input hatch on the top left (blue)
  3. Additive hatch on the top right (blue)
  4. Product output in the front (black)
  5. Slag output in the back (orange)

Graphite Electrodes can't be accessed from the world.