The Forge is a furnace fueled by an internal tank of lava. You can refill the tank by right-clicking the forge with a bucket of lava. It's inside the category of Machines.
Crafting EditThe furnace is crafted in a crafting table with 3 Ignatius ingots on the top, a machine frame in the middle, a furnace on the bottom and 4 Shadow Steel ingots to the sides.
4.0.0 - The many tiers have been removed, leaving a single forge.
4.0.6 - Rhino Kneel's texture was replaced with the texture from the new artist, EratoNysiad
- One bucket of lava smelts 99 blocks, in contrast to the furnace, which can smelt 100 per bucket, however, you don't have to smelt them all in one go.