Folder Name: 2318
Book Name: E06300_Modern_Workshop_Practice.pdf
Summary: mm for each full turn of the wheel and read the vernier. The reading of the size is taken to the nearest .00005 mm. Although the operation is simple, great precision is required in the manufacture of machines used for the metric system of measurement, both in the grinding of the measuring screws and the graduations on the wheels. The ranges given in the table above are for sizes which can be measured without resetting the gage. Each machine is provided with a number of spindles, so that a measurement can be made without disturbing the spindle having the size last measured. Measurements beyond a certain range require resetting of the gage. Since each reading is taken over a complete revolution of the wheel, adjustments on the instrument are made by means of locking screws which must be loosened before the gage can be reset. It will be observed that the readings of each machine are progressive, so that any machine can be quickly set to read any size from 10 mm to 20 mm by setting the spindle to the size desired and the other spindles will then be off any additional distance uniformly.