Refined Iron

Refined Iron is a component that was used to craft many IndustrialCraft 2 recipes before it entered experimental phase. Recipes using it replaced it with an Iron Ingot, a type of Plate (often Iron), or an Item Casing. It has been re-added, but as a form of Steel.

Recipe
Before IC2 Experimental #100, Refined Iron was created by smelting an Iron Ingot in a Furnace:

However in Build #527 and newer, it is created with the IC2 Blast Furnace: