Pre fabricated steel structure is a metal structure which is made of structural steel* components connect with each other to carry loads and provide full rigidity. because of the high strength grade of steel, this structure is reliable and requires less raw materials than other types of pre-structure like concrete structure and timber structure. in modern construction, steel structures is used for almost every type of structure including heavy industrial building, high-rise building, equipment support system, infrastructure, bridge, tower, airport terminal, heavy industrial plant, pipe rack, etc durability it can withstand extreme forces or harsh weather conditions, such as strong winds, earthquakes, hurricanes and heavy snow. they are also unreceptive to rust and, unlike wood frames, they are not affected by termites, bugs, mildew, mold and fungi.