Railroad spikes, also called RR spikes, are used to fasten the rail track to the tie plate. They hold the rail base against the plate and sleeper and resist the uplift, lateral, and longitudinal forces of passing trains. There are different types of railroad spikes on the market, primarily the dog spike and the screw spike. The choice of material determines the strength, toughness, and corrosion behavior of the spike in service.
Dog Spike Specifications
| Specification | Material | Surface | Standard |
| 5/8 inch by 6 inch | A3, Q235, 45 steel, 55 steel | Per customer needs | Per drawings or samples |
| 9/16 inch by 5-1/2 inch | A3, Q235, 45 steel, 55 steel | Per customer needs | Per drawings or samples |
| 3/8 inch by 3-1/2 inch | A3, Q235, 45 steel, 55 steel | Per customer needs | Per drawings or samples |
| 1/2 inch by 3-1/2 inch | A3, Q235, 45 steel, 55 steel | Per customer needs | Per drawings or samples |
Screw Spike Specifications
Screw spikes are produced in the Ss series including Ss5, Ss8, Ss25, and Ss36, and in the UIC 864-1 series. Raw materials include Q235, 35 steel, 45 steel, 40Mn2, and 20MnSi, with grades 4.6, 4.8, 5.6, and 8.8. Available surfaces are plain oiled, black paint, color paint, zinc, and hot dip galvanizing. The threaded shank gives the screw spike high pull-out resistance and makes it suitable for concrete sleeper fastenings with plastic dowels.
Materials Used for Railroad Spikes
Basically, railroad spikes are made of the following materials: Q235 carbon steel, Q345B carbon steel, Q345D carbon steel, 45 steel carbon steel, 40Cr steel, 35CrMoA steel, and 20MnTiB. Each grade offers a different balance of strength, toughness, weldability, and cost.
Properties of Common Spike Steels
Q235 carbon steel: good plastic property, toughness, and welding performance, with good cold pressing and bending behavior. It is used for parts and welded structures with average requirements.
45 steel: the most used medium carbon steel with good comprehensive mechanical properties, widely used for moving parts with higher strength, but it is easy to crack in cold pressing.
Q345 carbon steel: good comprehensive mechanical properties, good processing performance with cold and hot pressing, and good corrosion resistance. It is used in highly loaded welded structures such as ships, bridges, and crane equipment.
40Cr steel: after conditioning it has good comprehensive mechanical properties and low temperature impact toughness, but poor welding property. It is one of the most used alloy steels for shafts, pins, rods, screws, and bolts.
How to Choose the Spike Material
For general timber sleeper tracks where spikes are driven directly into the wood, Q235 or 45 steel provide the right balance of strength and cost. For heavy haul lines and high strength fastenings, use 40Cr or other alloy steels with higher mechanical properties. For welded structures and corrosive environments, Q345 offers better processing and corrosion performance. Match the grade to the required tensile strength, and confirm the surface finish according to the environment.
Features of a Quality Railroad Spike
A quality spike has a clean surface without cracks, scale, or sharp burrs, an accurate cross section, and a head that seats correctly on the tie plate. The spike must pass the required bend test without cracking, and the material must be verified against the order grade. Custom fabrication based on customer drawings ensures compliance with the technical standards of various countries and regions.
Frequently Asked Questions
What is a railroad spike used for? railroad spike fastens the rail track to the tie plate and sleeper, holding the rail base in place under traffic loads.
What are the two main types of railroad spikes? The two main types are dog spikes and screw spikes.
Which steel is most used for medium strength spikes? Q235 carbon steel is commonly used, while 45 steel suits parts with higher strength requirements.
Which material suits heavy haul fastenings? alloy steels such as 40Cr provide higher mechanical properties for heavy haul and high strength fastenings.
What surfaces are available for spikes? Plain, black, hot dipped galvanized, and sherardized finishes are available according to customer needs.
