What is a rail and how does it function?

Jan 23, 2026 Leave a message

What is a rail and how does it function?

 

A rail is a rolled steel section that forms the running surface and guidance path for train or crane wheels, and it is the most critical load-bearing element in any rail track system. Rails are installed in parallel pairs and fixed to sleepers or support beams using fastening systems, creating a continuous pathway that allows vehicles to move safely, smoothly, and efficiently.

 

steel rail

 

  • From a structural standpoint, the first function of a rail is to carry and distribute wheel loads. When a wheel contacts the rail head, very high contact stresses are generated in a small area. The rail's cross-section and steel grade are engineered to resist bending, shear, and rolling contact fatigue, and to spread these forces through the web and base of the rail into the sleepers and then into the ballast or concrete foundation. This load-transfer function is essential to prevent excessive track deformation and structural failure.

 

train rail

 

  • The second key function of a rail is to guide the wheels and maintain the correct track gauge. The rail head profile works together with the wheel tread and flange to keep vehicles centered on the track, even at high speed or under lateral forces in curves and during braking. Accurate rail alignment and profile are therefore fundamental to operational safety and derailment prevention.

 

track rail

 

  • A third function is to provide a smooth, continuous rolling surface that minimizes vibration, noise, and energy loss. Well-maintained rails reduce rolling resistance, improve passenger comfort, and lower wear on both wheels and track components. For this reason, rails are regularly ground or milled to restore the optimal head profile and remove surface defects.

 

What is the most common rail size?

 

The most common rail size refers to Standard Gauge, a track width of 1,435 mm (4 ft 8½ in), used by about 55% of the world's railways for passenger and freight transport across North America, Europe, China, and more. For the actual steel rail dimensions, 60 kg/m (or similar heavy rail profiles like 50 kg/m, 54E1, 115RE) are very common for mainline railways, chosen for strength and cost-effectiveness, featuring an I-beam shape for load distribution.

 

train rail

 

As a professional rail fastener supplier, GNEE RAILWAY RAILWAY can provide different standard steel rail such as GB,American, BS, UIC, DIN, JIS, Australian and South Africa which used in railway lines, cranes and coal mining.

 

GB Standard steel Rail

 

Classification Height(mm) Head (mm) Bottom (mm) Thick(mm) Weight (kg/m)
Light Rail 8 KG/M 65 25 54 7 8.42
9 KG/M 63.5 32.1 63.5 5.9 8.94
12 KG/M 69.85 38.1 69.85 7.54 12.2
15 KG/M 79.37 42.86 79.37 8.33 15.2
18 KG/M 80 40 80 10 18.06
22 KG/M 93.66 50.8 93.66 10.72 22.3
24 KG/M 107 51 90 10.9 24.46
30 KG/M 107.95 60.33 107.95 12.3 30.1
Heavy Rail 38 KG/M 134 68 114 13 38.733
43 KG/M 140 70 114 14.5 44.653
45 KG/M 145 67 126 14.5 45.546
50 KG/M 152 70 132 15.5 51.514
60 KG/M 176 73 150 16.5 60.64
Crane Rail QU 70 120 70 120 28 52.8
QU 80 130 80 130 32 63.69
QU 100 150 100 150 38 88.96
QU 120 170 120 170 44 118.1

 

JIS E 1103/1101 Standard Steel Rail

 

Standard: JIS E 1103/1101
Size Dimension(mm) Weight
(kg/m)
Length(m)
Head Height Bottom Thickness
JIS 15KG 42.86 79.37 79.37 8.33 15.2 9-10
JIS 22KG 50.8 93.66 93.66 10.72 22.3 9-10
JIS 30A 60.33 107.95 107.95 12.3 30.1 9-10
JIS 37A 62.71 122.24 122.24 13.49 37.2 10-25
JIS 50N 65 153 127 15 50.4 10-25
CR 73 100 135 140 32 73.3 10-12
CR 100 120 150 155 39 100.2 10-12

 

Australian 1085 Standard Steel Rail

 

Standard: AS 1085
Size Dimension(mm) Weight
(kg/m)
Length(m)
Head Height Bottom Thickness
31KG 63.5 117.5 108 11.5 31.5 8-25
47KG 70 141.3 127 14.3 46.5
50KG 70 154 127 15 50.8
60KG 70 170 146 16.5 61
68KG 73.4 186 152 17.5 67.6
73KG 70 157 146 32 73.63
86KG 102 102 165 84.11 85.5
89KG 102 114 178 51 89.81

 

DIN 13674-1-2003 Standard Steel Rail

 

Standard:DIN 536
Size Dimension(mm) Weight
(kg/m)
Length(m)
Head Height Bottom Thickness
A55 55 65 150 31 31.8 10-12
A55 65 75 175 38 43.1
A75 75 85 200 45 56.2
A100 100 95 200 60 74.3
A120 120 105 200 72 100

 

UIC 860 Standard Steel Rail

 

Standard: UIC860
Size Dimension(mm) Weight
(kg/m)
Length(m)
Head Height Bottom Thickness
UIC50 70 152 125 15 50.46 12-25
UIC54 70 159 140 16 54.43
UIC60 74.3 172 150 16.5 60.21

 

Since 2008, GNEE RAILWAY RAILWAY has been supplying steel rails of different grades for more than 18 years, steel rails from GNEE RAILWAY is highly recommened in China and abroad.Wtih cutting edge equipment, GNEE RAILWAY produces high quality steel rails that meet with requirements of most countries. Standard rail, head hardened rail, heavy rail,light rail,crane rail and other types are all available here, as one of the China main rail supplier, GNEE RAILWAY RAILWAY has been working on supplying economical green railway products all over the world.

 

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