What are Steel Angle Bars Or Steel Iron Bars? Steel Angle bars are the most basic type of rollformed steel. They are formed by bending a single angle bar in a piece of steel. Angle Steel Bar is ‘L’ shaped; the most common type of Steel Angle bar are at a 90 degree angle. The legs of the “L” can be equal or unequal in length. Steel angles bars are used for various purposes in a number of industries. Framing is one of the most common uses for steel angles, but The larger the steel angle bars, the more weight and stress it can bear.