A major North American transit agency was experiencing loosening of their track work fasteners. This was due to modern vehicles coming into revenue service, and generating much higher shock and impact in turnouts.

The loose nuts and bolts created many issues:

  • Public safety concerns.
  • Increased frequency of maintenance inspections.
  • Disruptions to revenue service.
  • Higher overall operational costs.

One of the main requirements was a one-piece part with a captive disc spring washer that can be installed with standard tools and bolts. And most importantly: Stay tight without loosening.


J.Lanfranco supplied ERM nuts in ⅞”-8UNC Gr.5. After several months of testing, there was no loosening and a routine inspection and maintenance schedule was re-implemented. This solution led to increased security and reduced operational costs.

The ERM also ensured:

  • Quicker initial installations.
  • Reduction of parts, and no forgotten or lost washers.
  • Fewer inspections required after installation.
  • Torque can be re-applied with hand tools (no power source is needed on-site).

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