Steel

Steel is a refined for of Iron Added by both Railcraft and GregTech. It requires either the Blast Furnace or the Industrial Blast Furnace for production. It is used for tools, armor and some higher tier machines.

Recipe
In a Blast furnace some (undamaged) Iron tools and armor can be blasted into steel ingots as well. Undamaged Steel armor and tools can be blasted back into Steel, especially handy for the steel materials that can commonly found in the village blacksmith.

Blast Furnace: