How do rail clips work?
Jan 28, 2026
A rail clip is a spring-force fastener that secures the rail by elastic compression rather than rigid locking, allowing controlled movement that reduces stress concentration in rails, sleepers, and baseplates. This function improves fatigue resistance of the entire fastening system. GNEE RAIL provides complete elastic clip categories including E-Type, SKL, Nabla, Pandrol PR, KPO, Deenik, Fast Clip, crane rail clips, and Russian-type clips, supporting metro lines, heavy-haul railways, and industrial crane tracks under multiple international rail standards.
What is the material of rail tension clip?
Rail tension clips (or elastic rail clips) are primarily made from high-grade forged spring steel, chosen for its high tensile strength, elasticity, and fatigue resistance. Key material grades include 60Si2MnA, 60Si2CrA, 55Si2Mn, and 38Si7, with a surface hardness generally between 40-48 HRC.
Key Characteristics of Rail Tension Clip Material:
- Material Types: Primarily forged spring steel, such as 60Si2MnA or 60Si2CrA, used to provide necessary clamping force.
| Material | 60Si2MnA | 60Si2CrA | 55Si2Mn | 38Si7 |
| Chemical composition(%) | C:0.56-0.64, Mn:0.60-0.90, Si:1.60-2.00, Cr:≤0.35, P:≤0.03, S:≤0.03 | C:0.56-0.64, Mn:0.40-0.70, Si:1.40-1.80,Cr:0.70-1.00 P:≤0.03, S:≤0.03 | C:0.52-0.60, Mn:0.60-0.90, Si:1.50-2.00,Cr:≤0.35 P:≤0.03, S:≤0.03 | C:0.35-0.42, Mn:0.50-0.80, Si:1.50-1.80, P:≤0.03, S:≤0.03 |
- Manufacturing Process: Hot forging is typically used to ensure a uniform microstructure, which is better than other metal-forming processes.
- Hardness & Quality: They are quenched and tempered to achieve a hardness of 40-48 HRC, ensuring durability under heavy, vibrating loads.
- Surface Treatment: To prevent corrosion, the clips are often treated with plain (oiled), oxide black, color painting, hot-dip galvanizing (HDG), or zinc plating.
How do rail clips work?
Rail clips (or elastic clips) securely fasten steel rails to sleepers using forged spring steel, exerting high clamping force-approx. two tons per clip-to prevent longitudinal and lateral movement. By deforming under load, they absorb vibrations, maintain gauge stability, and reduce noise, crucial for high-speed and heavy-haul tracks.
Key Functions and Working Principles:
- Clamping Force & Stability: They securely hold the rail base to the baseplate or sleeper, ensuring the track remains perfectly positioned and preventing warping.
- Elasticity & Vibration Damping: As a train passes, the clips deform slightly, acting as a spring to absorb, rather than transfer, shock and vibration, which reduces wear and noise.
- Preventing Movement: They prevent "rail creep" (longitudinal movement caused by temperature changes and traffic).
- Durability: Made of high-strength spring steel (often 60Si2MnA), they can withstand repeated deformation without breaking or losing their clamping force, enabling a "fit-and-forget" approach to maintenance.
Common Types:
- E-Type: Known for its high elasticity and ease of installation.
| Model | Diameter | Material | Under Pressure | HRC | Weight |
| E1609 | Ø 16mm | 60Si2MnA | ≥950kg | 44-48 | 0.43kg/pc |
| E1809 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.61kg/pc |
| E1813 | Ø 18mm | 60Si2MnA | ≥950kg | 44-48 | 0.62kg/pc |
| E2001 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2009 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2039 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2007 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2055 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2056 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
| E2063 | Ø 20mm | 60Si2MnA | ≥950kg | 44-48 | 0.80kg/pc |
- SKL Type: Common on concrete sleepers, offering high stability in bends and junctions.
| Name | SKL tension clamp |
| Material | 60Si2MnA 60Si2CrA 55Si2Mn 38Si7 |
| Hardness | 42-47HRC |
| Fatigue Life | for Dia.18 is 3 millions cycles without breaking |
| for Dia.20 is 5 millions cycles without breaking | |
| Surface | plain (oiled), Oxide black, color painting or according to customer requirement |
| Standard | DIN17221, BS970, GB/T1222 |
- KPO Clips: Used for, and often found in, heavy-duty applications.
- Fast Clip: A modern, pre-assembled, and versatile option.
| FC 1500 | FC 1600 | |
| Nominal Buckle Pressure | 1000 kgf | 1250 kgf |
| Buckle Pressure | > 16 kN | > 20 kN |
| Rail Resistance to Climbing | >7kN | > 9 kN |
| Insulation Resistance | >5 kO | >5 kO |
GNEE RAIL supplies E rail clips, SKL rail clips, Nabla types rail clips, KPO rail clips, and other customized types of rail clips,these rail clips are designed with high precision and made up of premium grade spring steel. GNEE has been the largest and most competitive production base of rail clip in China after more than 18 years' rail clip producing experience, and have qualification to tender nationally large and medium scaled rail projects. What's more, our rail clip can be customized according to clients' requirements.
