Contactless Thread Inspection

What is the Contactless Thread Inspection?

IIT is used for inspection of internal threads and bores. This amazing technology is based on measurement of capacitance between the probe and the thread. IIT is the only automated contactless technology that can check the thread quality along the complete length of any thread.

IIT Components
IIT profile - Nominal thread
IIT profile - Damaged thread
IIT profile - Short thread
IIT profile - Missing chamfer
IIT profile - Loose thread
IIT profile - chip inside thread

Detection Capabilities

How does it work?

System is based on measuring by capacitive sensor with toroidal sensing field. Sensor measures mean distance between hole/thread and probe. Sensor measures signal during insertion, which produces symmet­ric signal. Signal processing is carried out by our in-house algorithm, which takes into consideration specific sensing method and especially sensor characteristics about measured part. 

In the system different tolerances can be applied depending on the product and customer requirements for the thread quality. For example it is possible to evaluate presence and shape of chamfers through which sensor passes. System also provides calibration and teach-in capabilities, online visualization and statistical processing, storage of data about rejected parts and other data processing functions.

Measurement precision and repeatability depends on sensor cen­tering during measurement. Therefore, we supply a special holder, which gives the sensor a self-centering capability against meas­ured hole. 

IIT principle of capacitive thread measurement
IIT Manual Station


System Parameters

Measurement range:

M5 – M25 (custom sensors for higher dimensions)

Measurement speed:

approximately 1 part / s based on application


0.02 mm average

Inspection configuration:

teach-in based on the sample master parts

INSPECTION of Internal thread

Contactless threads inspection

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