A furnace doesn't just output cold usable results. You need to wait for them to cool down.
Mods introducing new content into the game.
Furnaces, assembling machines, production chains.
when using this, items shown in your crafting inventory show the hot metals. but they are missing their actual names
eg: iron plate is 'Unknown key: "recipe-name.iron-plate" (Recipe)'
Fixed in 1.1.0.
Found a couple more of them - presumably they are smelting variations - Hot pipe - Hot underground pipe
Fixed in 1.1.1.