What Does 115lb Rail Mean?
In the railway industry, selecting the appropriate rail profile is a critical engineering decision that dictates track safety, rolling stock wear, and long-term infrastructure maintenance cycles. Among the various rail profiles used across North America and international networks, the 115lb rail is one of the most widely specified for medium-to-heavy rail applications.
Whether you are sourcing materials for a class-1 secondary line, an urban transit network, or an industrial siding, this technical guide explains what a 115lb rail represents, its exact dimensional parameters, metallurgical choices, and common engineering pitfalls to avoid.
1. Deciphering the Standard: Weight and Classifications
The designation "115lb rail" refers to the nominal weight of the rail per unit of length-specifically, 115 lbs/yd (pounds per yard). In metric-based regions, this weight profile translates to approximately 56.9 kg/m (often rounded to 57 kg/m ). Consequently, this profile is internationally standardized as the TR57 Rail (or TR57 steel rail).
The letters "RE" stand for the American Railway Engineering Association (now AREMA), which established the modern recommended section design. Thus, AREMA 115RE Rail represents a highly standardized heavy-duty rail designed to meet the rigorous physical and dynamic demands of North American freight and transit operations.
2. Physical Dimensions of the 115RE Rail Profile
The geometry of the 115RE Rail Profile is engineered to distribute high vertical wheel loads while resisting lateral forces. Unlike older designs, the modern head profile utilizes compound curves to reduce initial wheel-contact stresses.
| Parameter | Metric (mm) | Imperial (inches) |
| TR57 rail height (Total Height) | 168.3 mm | 6-5/8 in |
| Base Width (Flange) | 139.7 mm | 5-1/2 in |
| Head Width (Topmost flat section) | 61.6 mm | 2-27/64 in |
| Head Width (Base of head corner) | 68.3 mm | 2-11/16 in |
| Web Thickness (Center) | 15.9 mm | 5/8 in |
| Standard Nominal Weight | 56.9 kg/m | 114.7 lb/yd (Nominal 115) |
3. Material Grade Selection
Selecting the correct steel grade is a balance between initial capital expenditure and life-cycle track maintenance. The matrix below serves as a starting point for track engineers determining the appropriate grade of 115RE (TR57) Railway Rail:
| Operating Conditions | Key Traffic Characteristics | Recommended Steel Grade | Primary Benefit |
| Standard/Light Freight | Low curvature, Axle loads < 25 tons | Standard Strength (SS / LA) | Most economical upfront cost, reliable elastic limit |
| Mixed Passenger/Freight | Moderate grades, Medium-density traffic | Intermediate Strength (IS / IH) | Enhanced resistance to plastic deformation on moderate curves |
| Heavy Haul & Tight Curves | Axle loads > 30 tons, high-wear zones | High Strength / Head Hardened (HH / LH) | Exceptional resistance to shelling, corrugation, and gauge-face wear |
💡 Engineering Support Hook: Choosing between carbon and low-alloy chemistry depending on your track curvature and axle load can dramatically impact the life expectancy of your line. If you are currently designing or upgrading a track layout, our technical team can review your alignment data and wheel-load profiles to recommend the most cost-effective steel grade.
4. Chemical Composition and Mechanical Properties
To ensure the AREMA 115RE rail steel performs reliably under cyclic stress, the chemistry and mechanical performance are tightly regulated under the AREMA 115 lb rail specifications:
Mechanical Properties of AREMA 115RE Rail Steel
| Specs | Steel Grade | Hardness | Tensile Strength | Yield Strength | Elongation |
| (grade shown on web) | HB | ksi | ksi | % | |
| AREMA(with Carbon Steel chemistry) | Standard Strength (SS) | ≥ 310 | ≥ 142.5 | ≥ 74.0 | ≥ 10 |
| Intermediate Strength (IS) | ≥ 350 | ≥ 155.0 | ≥ 105.0 | ≥ 10 | |
| High Strength / Head Hardened (HH) | ≥ 370 | ≥ 171.0 | ≥ 120.0 | ≥ 10 | |
| AREMA(with Low Alloy Steel chemistry) | Standard Strength (LA) | ≥ 310 | ≥ 142.5 | ≥ 74.0 | ≥ 10 |
| Intermediate Strength (IH) | ≥ 325 | ≥ 147.0 | ≥ 80.0 | ≥ 8 | |
| High Strength / Head Harderned (LH) | ≥ 370 | ≥ 171.0 | ≥ 120.0 | ≥ 10 |
Chemical Composition of TR57 steel rail
| AREMA 2019 | C% | Mn% | P% | S% | Si% | Ni% | Cr% | Mo% | V% | Al% |
| Carbon Steel | 0.74 - 0.86 | 0.75 - 1.25 | ≤ 0.020 | ≤ 0.020 | 0.10 - 0.60 | ≤ 0.25 | ≤ 0.30 | ≤ 0.060 | ≤ 0.010 | ≤ 0.010 |
| Low Alloy Steel (for Std Strength) | 0.72 - 0.82 | 0.80 - 1.10 | ≤ 0.020 | ≤ 0.020 | 0.10 - 0.50 | ≤ 0.15 | 0.25 - 0.40 | ≤ 0.050 | ≤ 0.010 | ≤ 0.005 |
| Low Alloy Steel (for Int. & High Strength) | 0.72 - 0.82 | 0.70 - 1.25 | ≤ 0.020 | ≤ 0.020 | 0.10 - 1.00 | ≤ 0.15 | 0.40 - 0.70 | ≤ 0.050 | ≤ 0.010 | ≤ 0.005 |
5. Quality Control
When preparing to buy 115 RE rail, you must ensure that every shipment is accompanied by a compliant Mill Test Certificate (MTC).
At our production and testing facilities, we subject every batch of 115RE track rail to strict quality control, including online ultrasonic testing and laser-guided dimensional verification. The MTC provides the ultimate proof of quality. When reviewing your MTC for compliance with the 115 RE rail specifications, always verify three critical points:
- Heat Number Traceability: Ensure the heat number stamped on the rail web matches the ladle analysis printed on the MTC.
- Chemical Match: Verify that the Carbon, Manganese, and Silicon levels fall within the tight ranges specified by AREMA.
- Mechanical Verification: Confirm that the Brinell Hardness (HB) test points along the rail head meet or exceed the target threshold (e.g., ≥ 370 HB for Head Hardened grades).
Get a Quote in 24 Hours
As an experienced 115RE rail manufacturer, GNEE RAIL maintain transparent manufacturing standards and structured quality tracking from the furnace to the seaport.
Global steel market factors and raw material trends heavily influence the 115RE rail price per ton. If you are preparing a commercial bid, estimating project feasibility, or requiring a formal CIF/FOB quote tailored to your local destination, please reach out to our logistics and commercial teams. We can supply a complete package of 115RE rails alongside their matching 115 lb rail matching tie plates and fasteners to ensure absolute compatibility and streamlined delivery for your project.
