Iron is a metal added by vanilla Minecraft. It can be obtained from Iron Ore and, less commonly, Tin Ore. Thermal Foundation adds three items made of this metal: Iron Gears, Iron Nuggets and Pulverized Iron.
Iron Ore and Tin Ore can also be processed in various ways in an Induction Smelter, with varying byproducts.
The metal is very commonly used as a low- to mid-tier crafting material. Iron can also be combined with Ferrous Metal to create the alloy Invar.