Ss35 Sleeper Screw With Uls7 Washer

The SS35 Sleeper Screw with ULS7 Washer is an advanced rail fastening system used in railway track construction and maintenance, providing secure, long-lasting, and stable track assemblies. It’s designed specifically for heavy-duty rail applications, such as those in high-speed rail systems, freight lines, and high-traffic commuter rail networks. The SS35 screw, when paired with the ULS7 washer, offers a combination of load-bearing strength, vibration resistance, and corrosion protection to ensure the track remains securely fastened for a long time. It is also named as Ss35 screw spike with Uls7 washer.

1. SS35 Sleeper Screw

Material

The SS35 sleeper screw is made from Q235,35,#45,or as required. The steel is often heat-treated to improve the mechanical properties.

Design & Dimensions

Diameter: The SS35 screw typically has a diameter of around 16 mm to 24 mm. This provides enough material to handle heavy dynamic loads without the risk of deformation or failure.

Length: The length of the SS35 screw ranges from 90 mm to 120 mm (depending on the specific application), ensuring that the screw is long enough to securely anchor into various types of railway ties (wooden, concrete, composite).

Thread Design: The SS35 screw features helical threads, which provide a firm grip when installed..

Functionality

The SS35 screw is primarily used to attach railway rails to railway ties (sleepers). The screw’s helical thread design allows for easy insertion and tight engagement with the tie.The screw’s ability to resist loosening over time is critical in high-speed and freight systems, where vibration and dynamic forces can cause traditional fastening methods (like cut spikes) to fail more quickly.

2. ULS7 Washer

ULS7 stands for "Universal Load Spread", meaning that this washer is specifically designed to help distribute the load more evenly between the screw and the sleeper. By reducing localized stress, it helps minimize damage to the sleeper and prevents the screw from becoming loose or deformed over time.The ULS7 washer is typically thicker and more rigid than standard washers. This ensures it can withstand high compression from the screw, creating a uniform pressure distribution across the area where the screw contacts the sleeper.

• Type: A flat washer designed to be used in conjunction with the Ss35 screw spike.

• Function: Provides a flat bearing surface, distributes the load, and helps ensure a reliable and stable connection between the rail components and the sleeper.By creating a smoother interface between the screw and the sleeper, the washer helps reduce friction during installation and ensures the screw remains securely in place. It prevents direct contact between the screw and the sleeper, which can lead to damage over time due to repeated pressure or movement.

The Ss35 screw spike with a Uls7 washer is a railway fastener with a size of 24 x L where L is 150mm to 240mm, available in grades 5.6 or 8.8. It conforms to standards UIC864-1 and is made for connecting rails to concrete sleepers. The spike's mechanical properties include a tensile strength of ≥500 MPa, yield strength of ≥300 MPa, and elongation of ≥20%. 

Specifications

• Dimensions and grades Size: 24 x L mm, with lengths L ranging from 150mm to 240mm.

• Head: Square or hexagonal.

• Material Grades: Available in 5.6 or 8.8. 

• Standards: ISO898-1UIC864-1NF F500-50 

Mechanical properties

• Tensile Strength: ≥500 MPa

• Yield Strength: ≥300 MPa

• Elongation: ≥20%

• Cold Bending: Crack depth on the threaded part is not to exceed 1.0mm after a 30° bend. 

• Surface finishes: Plain oiled,Blasted oiled,Oxide black,Zinc plated,Hot-dip galvanized (HDG),Dacromet,Sherardizing;