What Is a Screw Spike
A rail screw spike, also called a sleeper screw, rail screw, or lag bolt, is a medium or large metal screw used to fasten a rail base plate or rail. Such spikes are always fastened into holes bored into the tie sleeper, sometimes together with embedded plastic dowels. They are popularly used for rails with wooden sleepers, especially in America and Canada, where they replace cut spikes when higher holding power is required.
Materials and Grades
The screw spikes are typically made of high-strength carbon steel or alloy steel, such as Q235, 35# steel, or 45# steel, offering excellent tensile strength and wear resistance. Other materials include 40Mn2 and 20MnSi for higher strength requirements. The mechanical grades commonly supplied are 4.6, 4.8, 5.6, and 8.8, with grade 8.8 reaching a tensile strength of at least 800 MPa and a yield strength of at least 640 MPa. These products are suitable for high-speed rail, heavy-duty freight lines, and urban rail transit systems.
Surface Finishes
The standard surface for this product line is plain oiled, sometimes described as black oil finish, which provides temporary rust protection during storage and transport. Other available finishes include black paint, color paint, zinc plating, and hot-dip galvanizing. For the plain oil black finish, the spike keeps its natural steel color with a light oil film, making it a cost-effective choice for wooden sleeper track in dry climates.
Available Series and Specifications
Common types include the Ss5, Ss8, Ss25, and Ss36 series, as well as the UIC864-1 series, with thread sizes from M16 to M26 and lengths from about 130 mm to 200 mm. For example, Ss8-140 and Ss8-150 correspond to M24 by 140 mm and 150 mm, while Ss25-165 corresponds to M25 by 165 mm. All series can also be manufactured according to customer drawings.
Packaging and Delivery
The spikes are packed in export-grade anti-rust wooden boxes or steel pallets, with moisture protection, and labeled with specifications and batch numbers for easy on-site identification and installation. Shipping options include sea, rail, and land to ensure safe and timely delivery. Any quantity is viable, large or small, and a range of finishes is available, including hot-dip galvanized, black, sherardized, or self color.
Frequently Asked Questions
What is a plain oil black screw spike? It is a screw spike with a light oil film on the natural steel surface, providing temporary rust protection during storage and transport.
Which sleepers are screw spikes designed for? They are mainly used with wooden sleepers, and can also be combined with plastic dowels for concrete sleepers.
What grades are available for screw spikes? Grades 4.6, 4.8, 5.6, and 8.8 are commonly supplied, with grade 8.8 providing the highest strength in this range.
What materials are used for these spikes? Q235, 35# steel, 45# steel, 40Mn2, and 20MnSi are typical materials depending on the strength class.
Can screw spikes be customized? Yes, dimensions and thread designs can be manufactured according to customer drawings and samples.
