A Steel Joist is a structural element used to support floors or roofs in buildings. It is a type of open-web, lightweight steel truss that consists of horizontal top and bottom chords connected by diagonal web members. Steel Joist is commonly used in commercial, industrial, and residential buildings as they provide significant strength and stability while reducing the overall weight of the structure. This also has a high strength-to-weight ratio, which means it can support significant loads while minimizing the amount of steel needed.