The types of ISCOR Steel Rail are usually distinguished by weight. For example, the 50 rail we often say refers to the rail with a weight of 50kg/m, and so on, there are 38 rails, 43 rails, 50 rails, 60 rails, 75 rails, etc., of course. There are also 24-track and 18-track, but those are all old almanacs. Among them, rails with 43 rails and above are generally called heavy rails.