What Are E-Type Elastic Rail Clips?
E-type elastic rail clips are round-bar spring clips that hold the rail foot against the baseplate through elastic deformation, giving positive and durable rail alignment under heavy service. They are made from spring steel, normally with a bar diameter between 18 mm and 23 mm for the common models. The E-family covers many sizes - E1, E2, E3, E1609, E1809, E1817, E2001, E2006, E2009, E2055, E2056 and others - and each model is defined by its bar diameter, developed length, toe load and the shoulder geometry it mates with.
Common E-Type Clip Models and Parameters
The table below lists the standard E-series clips with their round bar diameter, material, under-pressure (rated toe load), hardness and unit weight.
| Model | Diameter | Material | Under Pressure | HRC | Weight |
|---|---|---|---|---|---|
| E1609 | Ø16 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.43 kg/pc |
| E1809 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.61 kg/pc |
| E1813 | Ø18 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.62 kg/pc |
| E2001 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2009 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2039 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2007 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2055 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2056 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
| E2063 | Ø20 mm | 60Si2MnA | ≥950 kg | 44-48 | 0.80 kg/pc |
Spring Steel Grades for Elastic Clips
Clip steel is chosen for the balance of elastic limit, fatigue strength and toughness. The chemical composition ranges below are typical for the four grades most often specified for rail clips.
| 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 |
60Si2MnA is the workhorse grade: silicon raises the elastic limit, and manganese improves hardenability and toughness. Heat treatment to HRC 44-48 gives the combination of high toe load and fatigue life required by fastening system tests such as EN 13146-4 repeated loading.
Selection Criteria: From Track Data to Clip Choice
Track design and loads: axle load, speed and annual tonnage decide the required toe load and the clip family.
Performance requirements: verify clamping force, deflection under load and fatigue life against the fastening system standard (EN 13481 series in Europe).
Clip specification: check bar diameter, toe load and weight against the baseplate or shoulder; a clip with the right name but wrong geometry will not develop rated force.
Compatibility: the clip must mate with the gauge block, baseplate and rail foot of the system it is bought for.
Corrosion protection: specify the finish (zinc, zinc flake, phosphate-and-oil) according to the line environment; coastal and tunnel routes need heavier protection.
Common Selection Mistakes
Ordering by model name without checking the dimensional drawing - two suppliers may use the same code for slightly different geometry.
Ignoring toe load and assuming all clips of one bar diameter are equivalent.
Selecting clips without confirming shoulder and gauge block compatibility, then discovering field fitting problems.
Overlooking the finish specification, which is the main defence against corrosion in humid and salt-laden environments.
Frequently Asked Questions
Q1: What does the number in an E-type clip model mean?
Model codes generally indicate the bar diameter family and the design variant. In the common table, E1609 uses a Ø16 mm bar, E1813 a Ø18 mm bar, and the E2000 series is built from Ø20 mm bar stock. Always confirm the exact diameter and dimensions from the supplier's drawing, because the code convention is not universal across suppliers.
Q2: What clamping force does an E-type clip provide?
The common E-series specification rates the under-pressure at ≥950 kg (about 9.3 kN). The real toe load delivered in service depends on the baseplate, gauge block and installation accuracy, and should be verified against the fastening system standard.
Q3: Which steel is standard for E-type clips?
60Si2MnA silicon-manganese spring steel is the standard grade, heat-treated to HRC 44-48. For higher strength requirements, 60Si2CrA or 55Si2Mn may be specified; 38Si7 is used in some European designs.
Q4: Can E-type clips be used on timber sleepers?
E-type clips are designed for fastening systems with shoulders or baseplates on concrete and steel sleepers. Timber sleepers are conventionally fastened with cut spikes or screw spikes, because direct elastic clip systems have no seat to anchor the clip toe.
Q5: What corrosion protection is applied to E-type clips?
Common finishes are zinc plating, zinc flake coating and phosphate-and-oil. The choice follows the project environment: coastal, tunnel and humid tropical lines generally require zinc flake or heavier zinc coatings so the clips pass the salt spray requirement of the project specification.
Q6: How long do E-type clips last in service?
Spring steel clips are designed to sustain millions of load cycles without fatigue failure - fastening system qualification under EN 13481 with EN 13146-4 test methods involves repeated loading of three million cycles and more. Actual life depends on installation quality, environment and the toe load applied.