LAPPABILITY OF END GAUGES AND MECHANICAL PROPERTIES OF THEIR NEAR-SURFACE LAYERS.

The lappability of end gauges is their most important functional property, on which the accuracy of attestation and reproduction of measurements depends. In proportion the lappability of gauges is lost several times faster than the dimension, and the producers of end gauges therefore endeavor to improve the quality of their lappability. The present article describes new methods and means of measurement which for the first time make it possible to evaluate microhardness accurately in such thin near-surface layers of end gauges. Another important property of the near-surface layers affecting the retention of lappability of end gauges is their ability to accumulate lubricant.