Screw Spike Ss35 with ULS7 washer | Direct Supplier

Screw Spike Ss35

An Ss35 screw spike with a ULS7 washer is a specialized, heavy-duty railway fastener primarily used to secure rail fastening assemblies into concrete sleepers (ties). This specific spike-and-washer combination is a core component of the widely used W14 rail fastening system (often associated with Vossloh configurations)

Structural Function & Assembly

• Clamping Assembly: The Ss35 screw spike passes through a tension clamp (such as an SKL14 clip) and a guide plate, anchoring directly into an embedded plastic dowel (typically the Sdu25 dowel) pre-cast inside the concrete sleeper. 

• The ULS7 Washer: The ULS7 flat washer sits immediately beneath the head of the screw spike. It distributes the immense clamping force evenly over the underlying rail clip or guide plate, preventing localized surface wear, metal gouging, or loosening caused by high-frequency track vibrations. 

Key Dimensions & Material Specifications

• Standard Sizes: The Ss35 spike typically features a thread diameter of 24 mm and standard lengths of 160 mm or 161 mm. 

• Mechanical Property Grades: Manufactured to international standards like UIC 864-1, The Ss35 spikes with washers are commonly produced in strength grades 4.6, 5.6, or 8.8. Grade 5.6 is a standard default, requiring a minimum tensile strength of 500 MPa and a yield strength of 300 MPa.

• Washer Material: The ULS7 flat washer is typically stamped from Q235 carbon steel or high-strength structural spring steel. 

• Surface Finishes: To withstand decades of extreme trackside weathering, water pooling, and stray electrical currents, the entire assembly is finished using plain oiled, hot-dip galvanizing (HDG), zinc plating, or Dacromet/Sherardizing coatings.

Primary Applications of Ss35 Screw Spike

• High-speed and heavy-haul railway lines utilizing concrete sleepers.

• Modern ballasted and non-ballasted track systems that demand high longitudinal rail restraint and gauge widening resistance.

If you have a requirement for Ss35 screw spike with a ULS7 washer, please contact Signum Rail Fastening for a quote. Signum can make Ss35 screw spikes with ULS7 washers according to the drawing and requirements.