Why Spring Steel Is Used
Elastic rail clips are made of high quality spring steel bars. These steels are generally low alloy manganese, medium carbon, or high carbon steels with a very high yield strength. Spring steel has excellent comprehensive performance including mechanical properties, fatigue resistance, hardenability, and physical and chemical stability. The raw materials of elastic railroad clips mostly include 55Si7, 60Si7, 65Si7, 55SiCr7, 60Si2MnA, 60Si2CrA, 55Si2Mn, and 38Si7 grades of spring steel.
Chemical Composition of Main Grades
| Grade | Carbon | Manganese | Silicon | Chromium |
| 60Si2MnA | 0.56 to 0.64 | 0.60 to 0.90 | 1.60 to 2.00 | 0.35 max |
| 60Si2CrA | 0.56 to 0.64 | 0.40 to 0.70 | 1.40 to 1.80 | 0.70 to 1.00 |
| 55Si2Mn | 0.52 to 0.60 | 0.60 to 0.90 | 1.50 to 2.00 | 0.35 max |
| 38Si7 | 0.35 to 0.42 | 0.50 to 0.80 | 1.50 to 1.80 | Not specified |
Phosphorus and sulfur are each limited to 0.03 percent. Production refers to DIN 17221, BS 970, and GB/T 1222, which control the composition, hardenability, and quality of spring steel for fasteners.
Hardness and Fatigue Life
After forming and heat treatment, E-type clips reach a hardness of 44 to 48 HRC, while tension clips reach 42 to 47 HRC. Fatigue testing verifies the material quality: 18 mm clips withstand at least 3 million load cycles without breaking, and 20 mm clips withstand at least 5 million cycles. These values confirm that the spring steel has the right combination of strength and toughness for repeated rail traffic loading.
Main Rail Clip Products
| Model | Diameter | Weight | Material |
| Type III | 18 mm | 0.80 kg | 60Si2MnA |
| E1609 | 16 mm | 0.43 kg | 60Si2MnA |
| E1809 | 20 mm | 0.61 kg | 60Si2MnA |
| E1813 | 18 mm | 0.62 kg | 60Si2MnA |
| E2001 | 20 mm | 0.80 kg | 60Si2MnA |
| E2055 | 20 mm | 0.80 kg | 60Si2MnA |
| E2063 | 20 mm | 0.80 kg | 60Si2MnA |
| Anti-theft clip | 20 mm | 0.25 kg | 60Si2MnA |
Standard tension clips are produced in 13 mm and 14 mm diameters from 60Si2CrA, 38Si7, and 60Si2MnA. Surfaces include plain oiled, oxide black, color painting, hot dip galvanizing, and zinc plating.
How to Verify Clip Material Quality
Check the material certificate of the spring steel batch, including the chemical composition and heat number. Confirm the hardness test values and the fatigue test report for the clip diameter used. Inspect the surface for cracks, scale, and decarburization, which reduce fatigue life. Customized production of rail clips is available according to drawings or samples, with the same material control applied.
Frequently Asked Questions
What material are elastic rail clips made of? Elastic rail clips are made of spring steel grades such as 55Si7, 60Si2MnA, 60Si2CrA, 55Si2Mn, and 38Si7.
Why is spring steel used for rail clips? Spring steel has high yield strength, excellent fatigue resistance, and good hardenability, which keep the clip elastic under repeated loading.
What is the hardness of E-type clips? E-type clips have a hardness of 44 to 48 HRC, while tension clips reach 42 to 47 HRC.
What is the fatigue life of rail clips? Fatigue testing shows at least 3 million cycles for 18 mm clips and at least 5 million cycles for 20 mm clips without breaking.
Which standards apply to clip spring steel? Clip production refers to DIN 17221, BS 970, and GB/T 1222.
