Joint Bolt M24x180

In complex rail networks, standard track bolts often fall short when dealing with high-stress areas like switches, turnouts, and insulated crossings. The Joint Bolt M24x180 (also widely searched as an M24x180 fish bolt or insulated rail joint bolt) is a specialized, extended structural fastener engineered specifically for thick, multi-layered rail assemblies. Its extra length provides the critical thread engagement necessary to secure heavy structural joint bars under immense dynamic wheel loads and extreme thermal forces.

Technical Specifications: M24x180 Track Bolt

Manufactured to survive severe operational environments, our heavy-duty fasteners meet rigorous international mechanical thresholds:

· Product Designation: Extended Heavy-Duty Rail Joint Bolt (M24x180)

· Material Matrix: Premium High-Strength Carbon Steel / Structural Alloy Steel

· Thread Profile: M24 (24 mm nominal diameter)

· Total Shank Length: 180 mm (Optimized for deep-profile and insulated assemblies)

· Thread Pitch: 3.0 mm coarse pitch for maximum stripping resistance

· Unit Weight: Approximately 0.77 kg per piece

· Primary Track Allocations: Switch Turnouts, Diamond Crossings, Insulated Rail Joints, and R-50/R-65 Heavy Mainlines

Specialized Engineering Applications & Mechanics

1. Clamping Force for Multi-Layered Insulated Joints

Insulated rail joints (IRJs) require thick polyurethane, fiberglass, or composite bonding plates to isolate electrical signaling currents. Standard 150mm or 160mm bolts cannot clear these added dimensions. The M24x180 joint bolt provides the exact clearance needed to pass through thick insulation layers while ensuring full, secure nut engagement.

2. Turnout and Switch Tie Stabilization

Railway turnouts experience severe lateral forces as trains divert from one track to another. The extended 180mm length allows this bolt to handle multi-component clamping—binding the rail, fishplate, and turnout reinforcing bars together into a single, rigid structural block.

3. Anti-Rotation Oval Neck Design

During high-speed maintenance installations, field crews use high-torque hydraulic wrenches. To prevent the fastener from spinning inside the fishplate, the bolt is forged with an oval neck (elliptic neck) or diamond neck. This geometry wedges seamlessly into the rail joint bar's pre-slotted holes, allowing efficient, single-sided torquing.

4. Advanced Metallurgy and Anti-Corrosion Coatings

To resist the catastrophic effects of hydrogen embrittlement and environmental rust, we utilize specialized heat treatments and coatings:

· Mechanical Integrity: Quenched and tempered to achieve structural Grades 8.8, 10.9, or 12.9.

· Coatings: Available in Plain/Oiled, Black Oxide, Hot-Dip Galvanized (HDG), or Dacromet (highly recommended for high-tensile railway applications).

· Compliance: Conforms to global benchmarks including GOST 11530-76 / 11530-93 / 11530-2014, DIN, ISO, AREMA, and BS standards.

Technical FAQ for Track Engineers

Q: Why use an M24x180 bolt instead of an M24x150 bolt?
A: The extra 30mm of length is specifically engineered to accommodate thick insulated joint bars, heavy-haul switch track components, and reinforcement plates where standard mainline bolts are too short to fit a heavy hex nut and spring washer.

Q: Which coating is best for high-tensile M24x180 railway fasteners?
A: Dacromet coating is highly recommended for high-strength steel (Grades 10.9 and 12.9) because it provides elite corrosion protection without causing hydrogen embrittlement. For standard environmental protection, Hot-Dip Galvanizing (HDG) is also highly effective.

Why Source from Signum Rail Fasteners China?

As a dedicated railway fasteners factory, Signum Rail Fasteners China delivers specialized, heavy-duty components built to precise client drawings and engineering tolerances.

· Continuous Production: Our 2-shift workforce handles high-volume industrial and mainline demands with minimized lead times.

· End-to-End Quality Control: From initial steel billet sourcing to ultrasonic flaw detection and thread gauging, our QC team guarantees zero-defect performance.

Request a Technical B2B Quote

Do your upcoming track layouts require high-performance, extended fasteners? Contact Signum Rail Fasteners today to receive a rapid, competitive price quotation on custom M24x180 rail joint bolts.