I-beams, also known as steel beams, are steel bars that bear weight in building structures. I-beams have a cross-section in the shape of an "I" and are categorized into three types: standard I-beams, light I-beams, and wide flange I-beams. Based on the height ratio of the flange to the web, they are further divided into wide flange, medium flange, and narrow flange I-beams. The production specifications for the first two types range from 10 to 60 numbers, indicating heights from 10 cm to 60 cm. At the same height, light I-beams have narrower flanges, thinner webs, and are lighter in weight.