Railroad spikes, also known as rail spikes, are designed to maintain the gauge between the running rails and to secure the steel rail to the railroad tie. Among the various railroad spikes, dog spikes and screw spikes are the most common types. Railway screw spikes are usually used to fasten railway ties or sleepers, and they can also be used together with plastic ferrules cast into concrete ties or sleepers. Screw spikes vary in thread profile, length, diameter, and drive head according to specific geographic requirements.
How a Screw Spike Works
The screw spike creates a mechanical interlock with the sleeper through its threaded shank. When driven, the thread pulls the rail base down against the tie plate or baseplate and resists uplift, lateral movement, and longitudinal creep. Because the holding power comes from the thread engagement over the full embedded length, the screw spike provides much higher pull-out resistance than a plain dog spike of the same size.
Screw Spike Types: Ss Series, Square and Hexagon Heads
| Type | Specification | Weight kg |
| Ss1/130 | M22 by 130 mm | 0.451 |
| Ss1/150 | M22 by 150 mm | 0.478 |
| Ss2/180 | M22 by 180 mm | 0.595 |
| Ss5/150 | M24 by 150 mm | 0.545 |
| Ss6/150 | M26 by 150 mm | 0.702 |
| Ss7/180 | M24 by 180 mm | 0.636 |
| Ss8/140 | M24 by 140 mm | 0.528 |
| Ss8/150 | M24 by 150 mm | 0.548 |
Standard surfaces are natural, zinc paint, or oil, according to customer needs, and the spikes can be produced to UIC, AREMA, or GB standards, or to customer drawings.
Square Head and Hexagon Screw Spikes.
Square head screw spikes are produced in M22 by 145 mm with materials such as 45 steel, 55Q, and Q235, and standard finishes of natural, zinc, paint, or oil. Hexagon screw spikes include several sizes such as M22 by 145, M22 by 155, M22 by 165, M22 by 185, and M22 by 195. The hexagon head is driven with a socket wrench, which suits fast mechanical installation.
Grades and Mechanical Properties
| Grade | Material | Tensile Strength | Yield Strength | Elongation |
| 4.6 | Q235 | 400 MPa or more | 240 MPa or more | 22 percent or more |
| 5.6 | 35 steel | 500 MPa or more | 300 MPa or more | 20 percent or more |
| 8.8 | 45 steel | 800 MPa or more | 640 MPa or more | 12 percent or more |
| 10.9 | 40Cr | 1000 MPa or more | 900 MPa or more | 9 percent or more |
All grades pass a 90 degree cold bending test without cracks. Surface options include plain oiled, oxide black, zinc, hot dip galvanizing, wax, bitumen, dacromet, and sherardizing.
Double-Head Screw Spike
The double-head screw spike has a screw head at both ends and is used in fastening systems popular in Africa. To meet the strict bending requirement, special raw material is applied and the spike is straightened so that it shows no cracks after bending 30 degrees or more. The common size is 23 mm by 174 mm, in grades 4.6 to 10.9, with raw materials such as 35 steel, Q235, and 45 steel.
Screw Spikes vs Dog Spikes
Screw spikes have screw threads on the shank, while dog spikes have a pointed penetrating head with a smooth surface.
In holding power, screw spikes provide more than twice the power of dog spikes.
Because of the greater fixing power and the ability to combine with spring washers, the cost of manufacturing screw spikes is higher than dog spikes.
Frequently Asked Questions
What is a rail screw spike? rail screw spike is a railroad spike with a threaded shank that interlocks with the sleeper to hold the rail in gauge.
What types of screw spikes are available? Common types are the Ss series sleeper screw, square head screw spike, hexagon screw spike, and double-head screw spike.
What is the specification of Ss8/150? Ss8/150 is M24 by 150 mm with a weight of 0.548 kg.
How much stronger is a screw spike than a dog spike? screw spike can provide more than twice the holding power of a dog spike of the same size.
Which standards apply to screw spikes? Screw spikes are produced to UIC, AREMA, DIN, and GB standards, or to customer drawings.
