Over the years we have looked at using air gaging and back pressure to measure small bores, generally under 1 mm/0.040”. Air gaging can be an acceptable way of doing this, but it does not provide any form information; it only provides the flow area as related to the diameter. However, because these holes are so small there may not be another economical solution.
But increase the size and there is a whole family of bore gages available to measure from 1 mm to 20 mm. In other words, a whole family of bore gages for these small bores. These precision mechanical bore gages use comparison to determine size and shape deviations of bores. Unlike fixed plug gages that employ a ground cylinder and sensitive contact to compare a bore to a master, these small comparative gages basically take the mechanical transfer out of the plug and use it as a standalone probe to measure small bores. Since there is no centralizing plug, the small-bore probe is rocked through the bore being measured to capture the smallest value related to the diameter of the bore, very much in the same manner as the tried and true adjustable bore gage.
Marameter 844 K Bore Gage System
The inside diameter measuring probes from the Marameter 844 K family have been a permanent feature of the Marameter hole measuring system for decades. Mahr has invested in a scrupulous overhaul of the probe family, and this tried and tested measuring system has been upgraded for the future. New materials, processes and options now ensure maximum linearity accuracy.
For more information about the Marameter 844 K Bore Gage System
