Creativerse Tooltip Tempered Iron Bar R31
Creativerse tempered iron bar forging10

The Tempered Iron Bar is a material that can currently only be made from Iron Bars (made from Iron Ore in a Forge) by re-forging them in the Forge (together with some Fuel).

Currently (as of R31 in May 2016) Tempered Iron Bars are necessary ingredients for crafting

You cannot find this material in treasure chests nor obtain it as a loot/pet-harvest. It also cannot be put in the quickbar nor placed into the world.