Angle steel, commonly known as Angle iron, is vertical to each other into the angular strip of steel. There are equilateral angles and unequal angles. The two sides of an equilateral Angle are equal in width. Its specifications are expressed in millimeters of side width × side width × side thickness. Such as "∟ 30 * 30 * 3", it indicates that the width of 30 mm, while equal Angle steel thickness is 3 mm. It can also be denoted by model number, which is the number of centimeters of side width, such as L3#