Steel (3.5e Equipment)
From D&D Wiki
Steel is the default metal used for weapons and armor. Ammunition, such as arrows and crossbows, may use cheaper iron.
Steel is iron ore with unwanted impurities removed and other impurities introduced. These impurities strengthen iron, making it far more resilient. Steel comes in many types. The steel for each weapon is assumed to be an appropriate type for that weapon.
Steel items have a hardness of 10 and 30 hp/inch. See Breaking Items for further information.
Iron from a wall of iron is not steel.