When most people think of railroads and tracks, they picture steel rails, sleepers, and ballast. What’s often overlooked? The fasteners that hold it all together. Track bolts, rail bolts, and fish bolts may not be as prominent as the tracks themselves, but they’re absolutely critical to railway safety and durability.
So, let’s dive into what these bolts are, where they’re used, and what standards you should pay attention to when specifying them.
What Are Track Bolts & Rail Bolts?
Track bolts (sometimes called rail bolts) are heavy-duty fasteners that secure rail components to sleepers, tie plates, and fishplates (joint bars). These bolts:
- Have special profiles like square or oval necks to prevent rotation
- Are usually supplied with high-strength nuts and washers
- Are often heat-treated and coated to survive extreme vibrations and weather exposure
Rail bolts and track bolts need to withstand repeated dynamic loads as trains pass by at high speeds. They’re a vital part of ensuring that rails don’t shift, loosen, or break under stress.
What Are Fish Bolts?
Fish bolts (also called joint bar bolts or splice bolts) are specifically used to connect two rail ends together using fishplates. Unlike regular bolts, they’re designed with:
- Oval or elliptical necks to fit snugly into fishplate holes
- Smooth domed heads to reduce wear on train wheels
- Matching oval holes to prevent bolt rotation during installation
Fish bolts must maintain tight clamping force to prevent rail end gaps, which could cause bumpy rides—or worse, derailments.
Common Applications
Here are some typical situations where you’ll encounter these bolts in action:
- Track Bolts / Rail Bolts:
- Securing rails to tie plates and sleepers in all kinds of railway infrastructure.
- Holding rail chairs and baseplates for smooth and stable track alignment.
- Fastening guard rails and check rails on bridges and switches.
- Fish Bolts:
- Joining rail ends with fishplates or splice bars.
- Installing in areas needing rapid assembly and regular maintenance.
- Common in continuous welded rail sections where joints must remain perfectly flush.
Specifications & Standards
Track and fish bolts must conform to strict international standards to ensure safety and interoperability. Some of the most common standards worldwide include:
| Region | Common Standards |
| North America | ASTM A183, AREMA, SAE Grades 5 and 8 |
| Europe (Germany, France, Netherlands) | DIN 5902, EN 13674, ISO 898-1 |
| South Africa | Frequently aligned with DIN EN ISO standards for rails and fishplates |
Standard diameters often range from M20 to M24 (¾” to 1”), with lengths that suit typical rail chair and fishplate thicknesses. Finishes typically include:
- Hot-dip galvanizing per ISO 1461 for corrosion resistance
- Plain/oiled finish for temporary setups or dry environments
- Black oxide or zinc plating for light-duty or interior applications
Why Bolt Selection & Installation Matter
Choosing the right bolt isn’t just about size and length. Consider:
- Grade & Strength: Higher-grade steel for heavy loads or high-speed rail.
- Head Design: Oval-neck bolts to lock into fishplates? Square-neck bolts for rail chairs?
- Coating: Exposure to rain and salt spray? Go for galvanized.
- Assembly: Do you need pre-assembled sets (bolt + nut + washer)? Speed up installation with matched kits.
And never forget proper torqueing and tensioning. Even the best bolts fail if installed incorrectly.
TUHU Fasteners: Supporting Rail Infrastructure
At TUHU Fasteners, we manufacture and export a full range of track bolts, rail bolts, and fish bolts:
- Available in standard or custom lengths and diameters
- Conforming to ASTM, DIN, ISO standards as required
- Coated and packaged per project specification
- Ready for immediate shipment to North America, Europe, Africa, and beyond
Whether you’re assembling new rail lines, repairing fishplates, or replacing bolts on existing track, TUHU is here to help you stay on schedule and on track.
Ready to Source Track & Fish Bolts?
Whether you’re upgrading a railway track, assembling new fishplates, or looking for high-quality track bolts and fish bolts, TUHU Fasteners has you covered. Our products meet international standards like ASTM, AREMA, DIN, and EN — delivered worldwide with full certifications and export-ready packaging.
👉 See Our Rail & Track Bolt Products
🤝 Reach out today for a custom quote — we’ll help you keep your rails strong and your projects on schedule.
Let’s keep the wheels turning—safely, securely, and efficiently.