Technical Guide to 115RE Track Bolts for Rail Joint Assemblies

Maintaining the structural integrity of mechanical rail joints requires heavy-duty, highly engineered fasteners. For standard 115RE (115 lbs/yd) rail profiles, also known as TR57, selecting the exact track bolt configuration is critical to preventing joint failure under heavy freight and transit loads.

Signum will guide you on how to select track bolts in two blog posts. This article focuses on fundamental knowledge.

Below is a technical breakdown of 115RE track bolt dimensions, engineering types, and installation standards.

Heavy Rail Sizing and Nut Match Chart for 115RE

For standard 115RE AREMA rails, hardware sizing relies on exact clearances within the fishplates (joint bars). Standard 115RE joint bars are stamped or drilled with 1-1/8” diameter holes to easily clear the 1-inch track bolt shank.

The industry standard hardware configurations for this rail class include:

· Standard Bolt Size: 1” diameter × 6” length (1" × 6").

· Alternative Bolt Size: 1” diameter × 5-1/2” length.

· Type E Track Bolt: 1” diameter × 5-1/4” length.

· Head Style: Button Head Oval Neck (BHON).

· Standard Nut Style: Heavy Square Nut (Heavy Hex or Self-Locking nuts are used based on engineering preferences).

· Washer Accompaniment: High-strength AREMA Spring Washer.

Engineering Types of Railway Track Bolts

A functional 115RE track joint fastener relies on three distinct components engineered to form a single, anti-loosening unit:

1. Button Head Oval Neck (BHON) Track Bolts: The unique oval neck beneath the smooth, rounded button head drops perfectly into the matching oval-punched joint bars. This physical mechanical lock prevents the bolt shaft from turning while crews tighten the assembly from the opposite side.

2. Heavy Square Track Nuts: Heavy square nuts provide a wider footprint and thicker profile than standard commercial hardware. This maximizes surface-contact friction against the joint bar flange, preventing the nut from backing off under high-frequency track vibrations.

3. AREMA Spring Washers: These structural split washers maintain continuous tension on the fastener assembly, absorbing the heavy live-load stresses of rolling train wheels.

Installation Criteria for Railway Track Bolts

To satisfy structural safety standards and ensure maximum clamping force, railway track crews must adhere to strict installation protocols:

· Alternating Directions: Bolts must be inserted through the joint bars in alternating directions (one from the field side, the next from the gauge side) along the joint assembly to distribute structural load evenly.

· High Torque Target: Track bolts require tightening to approximately 400 foot-pounds of torque.

· Clamping Tension: Proper torquing generates roughly 25,000 to 30,000 pounds of tension, completely flattening the spring washer to counter heavy freight disruptions.

· Component Compliance: Every functional joint assembly must consist of a certified carbon steel BHON bolt, an AREMA-approved spring washer, and a matching heavy nut.

Global Procurement for AREMA Fasteners

Signum Rail Fasteners China manufactures premium railway track bolts and heavy square nuts manufactured from high-grade carbon steel. Every batch complies strictly with AREMA and international standards to deliver the strength required by high-tonnage rail lines.

We supply custom structural fasteners according to our clients’ engineering drawings and specific project requirements to networks across North America, Europe, and worldwide. Backed by a rigorous quality control team and responsive after-sales service, our track hardware delivers dependable longevity for global rail infrastructure.