Thanks to its high accuracy, even measurements below the micron range present no problems. The basic unit is a column of fine-grained hard stone fabricated with maximum precision. Temperature effects are minimised thanks to its symmetrical, homogeneous shape. The generously dimensioned base surface ensures highly accurate measurements.

The measuring saddle: The patented measuring saddle is held to the guideway of the column by a vacuum and is thus slightly pretensioned. A flow control valve modulates the pretension force to allow optimal adjustment of the saddle displacement. The material properties of the saddle and the guideways are ideally matched, thus assuring high accuracy over many years. A security groove in the column prevents the saddle from tilting forwards and getting damaged.

Vacuum generation: The SQUARE-plus is supplied with air from the in-house compressed-air system. The vacuum unit is integrated in the upper terminal plate. The SQUARE-tool alignment bracket or other vacuum-operated accessories can be connected directly to the instrument.


Factsheet SQUARE-plus


Technical Data

Type Travel Squareness frontal Squareness lateral Dimensions (L×W×H) Weight Required compressed air Air consumption Measurement reading Repeatability
other variations

The accuracy values apply to 20 °C and stable temperature conditions (ΔT ≤ 0.2K / 24h).

For special solutions and other dimensions please contact us: Contact.



Calibration Set for Knife-Edge Squares

Kunz precision presents a simple but unique solution for measuring knife-edge squares: Hereby the new developed lever gauge GT 31-TK is employed. The measuring probe shows a cylindrical touching surface with two markings in between which the test piece is being probed. In this way, the inner and outer leg of the test piece can be measured quickly and straightforward.



SQUARE-tool is an ingenious device for even faster and more efficient measurements, with vacuum exhaust. The positioning aid is used together with the squareness measuring devices SQUARE-line, SQUARE-plus, SQUARE-control and SQUARE-master.


Measuring Probes

We have several probes in our range.


Measuring Probe Mounting SQUARE

This measuring probe mounting allows to measure inner surfaces with the squareness measuring instruments SQUARE-line and SQUARE-plus in the simplest way. This simple and practical accessory consists of a temperature insensitive extension tube of aluminium or carbon fiber and a probe holder.