Measurement of diameter and length

Plunger probes

Plunger probes are universal bore gauges for indicating internal measurements

Features of the indicating 2-point gauges are easy handling, adaptability to most bore gauging applications and large measuring ranges. They are often used for single measurement of larger diameters.


  • Range of application:
  • Standard plunger probes: Ø 19.5 – 332.0 mm (0.768 – 13.071 Inch)
  • Blind bore style (FB): Ø 38.5 – 343.0 mm (1.516 – 13.504 Inch)   

The standard plunger probes are produced in four different sizes (MK5, MK6, MK7-plus and MK8-plus). The blind bore styled plunger probes are offered in two different designs (MK6FB and MK8FB).

Accuracy of standard style: repeatability is = < 1 um

Zero setting of the gauge can be made in a setting ring, slip gauge, setting device or a centering disk which is clamped onto a micrometer spindle (not suited for style FB).

Sets of plunger probes in a wooden box can be purchased, e. g. with a measurement range of 50.5 to 332 mm.

 In addition to check of diameters, plunger probes can detect shape deviations of bores such as taper, barrel shape, out-of-roundness etc. Plunger probes can also be used for gauging parallel distances.As an alternative to mechanical indicators with a resolution of 0.01 resp. 0.001 mm digital min-max indicators as for instance MDU-M125 can be used. These ones can transfer the measured values via DIAWIRELESS. Special shapes and solutions on request.


Plunger Probes operating instructions