Nabla RNTC Spring Clip for Railway Fastening Systems

The Nabla RNTC spring clip is a specialized elastic blade used within the Nabla RNTC rail fastening system, primarily for urban transit and specialized track beds. It is distinct for its application with STEDEF track technology and profiled concrete sleepers. 

Technical Features

• Design: It is a trapezoidal spring blade made of alloy spring steel (typically 60Si2MnA or 60Si2CrA in China).

• Toe Load: 2500 DaN once the securing nut is torqued to contact.

• Durability:3 million cycles without breaking.

• Hardness: 42–47 HRC or 51–55 HRC depending on regional standards. 

Application & Compatibility

• Rail Types: Specifically optimized for grooved rails used in tramways and light rail transit (LRT), such as 60Ri1, 60Ri2, 62Ri1, and 62Ri2.

• Track Beds: Highly versatile, it can be installed in ballasted tracks, slab tracks, or embedded in concrete, asphalt, and green (grass) track beds.

• Environmental Benefits: Effectively reduces vibration and ambient noise, making it suitable for residential urban areas. 

System Assembly

The RNTC clip works as part of a multi-component assembly to maintain track gauge and stability:

• Nabla RNTC Blade: The primary elastic fastening component.

• Rail Insulator: Provides electrical insulation (often >10 K Ohms) and lateral force absorption.

• Screw Spike & Nut: High-strength bolts that secure the blade to the sleeper.

• Rail Pad: A resilient rubber or plastic cushion placed between the rail and sleeper to dampen shocks.