Attaching the clamp to the grounding cable requires the use of a ferrule. Ferrules are compressed on the strands of the cable
to provide a low resistance permanent connection. The size of the ferrule is determined by the size of the cable. Ferrules
are available in aluminum or plated copper. Plated copper ferrules can be used with either aluminum or bronze clamps.
Aluminum ferrules can be used with aluminum clamps only. Two ferrules are required for each assembly therefore they
are sold in pairs. Ferrules are manufactured to the specifications of ASTM F 855. *STB stocks tin-plated copper, unshrouded


  • Shrouded or unshrouded?
    Shrouded ferrules are compressed on both the conductor and the insulating jacket of the high voltage EPR cable to reduce
    bending stress. Shrouded ferrules are designed to be used on glove installed high voltage jumpers.
  • Threaded or plain plugged?
    Ferrules are manufactured of 99.5% pure copper with industry-standard 5/8” – 11 NC threads. Ferrules are topped with
    a brass hex jam nut and toothed stainless steel lock washer. Ferrule sold in an assembled
    jumper or temporary grounding set.


  • Provides positive stress relief of grounding cables at their terminations
  • Clear heat shrink allows visual inspection of cable strands and termination
  • Heat shrink materials provide a barrier to resist moisture and corrosion at the termination

Many ferrules are available for different terminal types: bolted, threaded, compression-bolted, and factory-installed
ferrules with heat shrink and threaded with heat shrink.