FALSE PIVOT

The false pivot, also called pivot-Gauge, is a measuring instrument shaped like a pivot intended to check the diameter of holes, particularly those of horological jewels. It comes in the form of assortments: a series of calibrated pivots whose diameters increase in very fine intervals, often on the order of a few microns (for example 0.0025 mm). By successively inserting the false pivots into a hole until finding the one that fits, the Horologist (watchmaker) precisely determines the size of the drilling or seat, in order to match a pivot or jewel to the desired Set. This tool illustrates the fine metrology specific to horology, where the Testing of inner diameters is decisive for the quality of operation: a hole that is too wide creates play and vibrations, a hole that is too tight jams the wheel. Simple but highly useful, the false pivot completes the range of gauges on the Bench.