Rail is the main component parts of the railway track. It's function is to guide wheel rolling forward, under the enormous pressure the wheel, and passed to the sleepers. Rail wheels must provide continuous, smooth and rolling surface of least resistance. In Electric Railway or automatic block section of rail track circuit can be used also cater. 

 The type of rail, 1 m or less per kg number indicates the quality. At present, our main types of railroad rail 75kg / m, 60kg / m, 50kg / m and rail 
 43kg / m the world's most heavy rail has reached 77.5kg / m, our lines are gradually laying heavy 75kg / m rail. 
 Standard rail length is 12.5m and 25m the two. 
 (1) classification. 
 Rail weight per meter kg or less the number of heavy rail and light rail can be divided into two types: ① heavy rail. Steel by the steel is divided into: normal manganese rail, copper carbon steel rail, rail steel with high silicon copper, brass rails, rail manganese, silicon and other tracks. There are three types of 38,43,50 kg. There are also a few lines of 45kg for the track, has planned large volume and the speed high with the 60kg rail line. China GB2585-81 provides 38 ~ 50kg / m rail technical conditions, such as its size and code shown in Table 6-7-10. ② light rail. Species in the "8" standard (5) requirements. There are various tracks 9,12,15,22,30 type, and the section size and types of rail-type shown as 6-7-11. Technical requirements see "8" in the standard (3).