Probe Terminology

Plunger Tip

  • Contacts the Unit Under Test (UUT).
  • Proper configuration is critical for good contact and electrical performance.

Plunger Shaft

  • The cylindrical part is critical to pointing accuracy of probe assembly.
  • Primary point of electrical contact between plunger barrel.
  • Probe life is influenced by the plunger shaft’s wear characteristics.


  • A precise deformation of the barrel at a specific location retains the plunger tail.
  • A spin crimp, dimple crimp, or a roll over crimp may be used depending on the probe series.

Plunger Tail

  • The enlarged bottom part of the plunger that retains the plunger.
  • Secondary point of electrical contact between the plunger and the barrel.


  • Housing for spring and guides the plunger.
  • Typically completely housed by the mating receptacle.
  • Important electrical link between plunger and receptacle.


  • Helical coil spring for maintaining a consistent counter force to the plunger.
  • Force determined by application.
  • Base material determines probe performance in extreme temperatures.

Receptacle Terminology:

Press Ring

  • Larger than recommended mounting hole; deforms slightly for press-fit into mounting hole.

Alignment Bulge

  • Aligns receptacle in mounting hole prior to installation.

Barrel Housing

  • Critical electrical link which houses the barrel of the probe.


  • Provides retention and electrical connection to probe barrel.
  • Single or multiple detents based upon size.

Wire Termination

  • Means to connect wire for electrical passage.
  • Configured for crimping, soldering, wire wrapping, terminal insertion, or with preattached wire.