How tall is a 115 lb rail?

If you are planning a rail infrastructure project, sourcing materials for industrial siding, or maintaining heavy-haul tracks, understanding the precise dimensions of your rail profile is critical.

The short answer is: A standard 115 lb rail (also known as a 115 RE rail) is exactly 6-5/8 inches tall, which is equivalent to 168.3 mm (or 168.28 mm).

Below, we provide a complete technical breakdown of the 115 RE rail section, its standard tolerances, compatible accessories, and practical installation considerations according to AREMA standards.

For quick reference, the table below outlines the primary nominal dimensions of a standard 115 RE rail in both imperial (inches) and metric (millimeters) units.

Detailed Technical Specifications (115 RE)

To ensure proper wheel-rail interface and track stability, railway engineers rely on highly specific curvature and slope details. When reviewing a standard 115 RE rail section drawing, several key geometric details are prominent:

• Head Geometry: The running surface features a primary compound radius starting with R203.2 mm (8 inches) at the top center, transitioning to R44.5 mm (1.75 inches) at the corners, and R14.3 mm (0.56 inches) on the side corners. This specific contour is designed to reduce initial wheel-rail contact stress.

• Side Slopes: The sides of the rail head feature a slight taper of 1:40, which helps guide wheel flanges smoothly.

• Fishing Angles (Slopes under the Head and top of the Base): Both the underside of the head and the top surface of the base flange have a steep 1:4 slope. These flat, angled surfaces (known as fishing surfaces) are crucial because they host the joint bars (fishplates) and must match them precisely to prevent joint sagging or vertical movement.

• Web Design: The web is 15.9 mm (5/8") thick at its narrowest point, with transitional fillet radii of R19.05 mm and R355.6 mm to distribute load evenly and mitigate stress concentration.

In North American railway terminology, rails are classified by their weight per yard of length. While commonly rounded up and referred to as a "115 lb rail," the actual theoretical weight of the 115 RE profile is 114.7 pounds per yard (approximately 56.9 kilograms per meter).

The "RE" designation indicates that the profile is designed in accordance with the specifications of the American Railway Engineering and Maintenance-of-Way Association (AREMA). In some international standards or European terminology, this profile is also designated as TR57 due to its linear mass being close to 57 kg/m .

1. Can a 115 RE rail be joined to a 136 RE rail?

Yes, but they cannot be joined with standard flat joint bars due to the difference in overall height (168.3 mm for 115 RE vs. 185.7 mm for 136 RE). Joining them requires specialized Compromise Joint Bars or transition welding to ensure a smooth, level transition on the running surface.

2. What is the standard length of a 115 lb rail?

In North American standard practice, new rails are typically delivered in 39-foot or 80-foot lengths. However, for international logistics or specific site constraints, they can be custom-cut to lengths such as 12 meters, 25 meters, or other specified dimensions.

3. How do I know if I need a standard carbon or a head-hardened 115 RE rail?

Standard carbon rails are generally sufficient for straight tangent tracks with light to moderate traffic. If your rail line features curves sharper than 3 or 4 degrees, or if it carries high-tonnage freight frequently, head-hardened rails are often preferred to resist vertical wear and plastic deformation.

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Selecting and purchasing the correct rail profile involves verifying your specific axle load requirements, expected traffic density, and compatibility with existing track structures.

As a supplier of industrial and railway track materials, GNEE RAILWAY RAILWAYL provide AREMA-standard 115 RE steel rails along with matching joint bars, tie plates, track bolts, and rail anchors. We focus on assisting project engineers and procurement managers with verified technical support, mill certificates, and logistic coordination.

If you require a detailed quotation, technical drawings, or have specific questions regarding steel grades for your project, please contact our technical support team for assistance.