H-beam products come in a variety of specifications and are categorized as follows: (1) By flange width, they are divided into wide flange, medium flange, and narrow flange H-beams. The width of the flange B for wide and medium flange H-beams is greater than or equal to the height of the web H. The width of the flange B for narrow flange H-beams is approximately half the height of the web H. (2) By application, they are categorized as H-beam beams, columns, piles, and extremely thick flange H-beam beams. Parallel leg channel steel and parallel flange tee steel are sometimes also included in the H-beam range. Narrow flange H-beams are generally used as beams, while wide flange H-beams are used as columns, leading to the terms beam-type H-beams and column-type H-beams. (3) By production method, they are classified into welded H-beams and rolled H-beams. (4) By size specification, they are categorized into large, medium, and small H-beams. Products with a web height H of 700mm or more are typically called large, those between 300 to 700mm are medium, and those less than 300mm are small. By the end of 1990, the largest H-beam in the world had a web height of 1200mm and a flange width of 530mm.

Internationally, the product standards for H-beams are divided into two major categories: the British Imperial System and the Metric System. Countries such as the United States and the United Kingdom use the Imperial System, while China, Japan, Germany, Russia, and other nations use the Metric System. Although the units of measurement differ between the two systems, H-beams are generally specified using four dimensions: web height (h), flange width (b), web thickness (d), and flange thickness (t). Despite the different methods of expressing the size specifications of H-beams across the world, the range of product size specifications and tolerances produced is quite similar.