Rail Plastic Dowel: Concrete Insert for Track Fastening

What Is a Rail Plastic Dowel?

A rail plastic dowel is a high-performance polymer insert embedded into pre-drilled holes in concrete sleepers. It acts as a mechanical anchor for fastening elements such as rail screws, clips, or bolts, ensuring that the applied clamping force remains stable and effective over time.

Typically made from engineering-grade plastics resistant to wear, temperature variations, and environmental exposure. 

Designed to fit precisely with sleeper holes and fastening screws, providing maximum grip and load transfer. 

Signum Rail Fastening is able to provide rail plastic dowels according to clients' drawing and requirements. We are good at offering rail plastic dowel Sdu25, Sdu26, Sdu9 and some rail dowels for tunnel constructions.

Key Functions of Rail Plastic Dowels

1.Secure Screw/Screw Spike Fixation 

oProvides a stable seating for screws or bolts used in rail fastening systems, preventing loosening under repeated train loads. 

2.Load Distribution 

oDistributes the clamping force of the screw over a larger area of the concrete, reducing stress concentration and the risk of sleeper cracking. 

3.Durability & Maintenance Reduction 

oPrevents metal-to-concrete contact, reducing wear and corrosion over time. 

oEnhances the long-term reliability of the track fastening system, minimizing maintenance needs. 

4.Vibration and Shock Absorption 

oThe polymer material helps absorb dynamic loads, reducing vibration transfer to the sleeper and rail. 

Applications of Rail Plastic Dowels

Rail plastic dowels are commonly used in concrete sleeper fastening systems with:

• SKL/W-type clip systems (e.g., SKL21, SKL30) 

• Pandrol E-Clip fastening systems 

• Heavy freight, passenger, and metro lines 

• Track renewal and new construction projects 

Advantages of Using Rail Plastic Dowels

Technical Considerations of Rail Plastic Dowels

When selecting or designing rail plastic dowels:

• Ensure compatibility with screw diameter and type. 

• Match the hole depth and diameter in concrete sleepers for optimal grip. 

• Choose materials with high wear resistance, UV resistance, and temperature tolerance. 

• Confirm compliance with railway standards (e.g., AREMA, NF F50-015, DIN). 

Conclusion

The rail plastic dowel is a small but critical component in modern railway fastening systems, serving as a durable, reliable, and corrosion-resistant concrete insert. By providing stable screw fixation, load distribution, and vibration absorption, plastic dowels ensure the safety and longevity of rail tracks under heavy operational loads.

For suppliers and track engineers, investing in high-quality plastic dowels ensures consistent track performance and minimizes maintenance costs over the lifespan of the railway infrastructure.

Signum Rail Fastening (Kunshan Signum Machinery Technology Co., Ltd.) is a specialized supplier that offers rail plastic dowels, dog spikes, tie plates, track bolts and other fasteners railway fastening systems.