Sunnen's PG Bore Gages take an intuitive approach to hole gaging with a mechanical design and speedometer-type scale for quick visual confirmation of ID (inside diameter) by a busy machine operator. The gage combines lab-precise accuracy (±0.000025"/0.0006 mm) with a shop-hardened design that’s compact, portable and mountable on machining stations. PG gages can be used to examine the entire bore for diameter, taper, barrel, bell mouth, out-of-round and lobing. A sliding faceplate with adjustable stops permits end-to-end examination of bores. Stops can be set to allow examination of a particular section of the bore, with accuracy right up to the edge of ports, lands and ends. The speedometer-type scale provides readouts down to 0.000050"(.001 mm) for 100 percent inspection of machining operations or fast sampling of large vendor lots. Various models are available for gaging IDs from 0.090" to 4.310". Metric models cover IDs from 2.0-109.47 mm. The PG Bore Gage removes complexity, skill and "feel" from the measurement process, allowing machine operators to precisely confirm part size with an intuitive analog scale. The unique design of these gages is not affected by temperature, moisture, air pressure, or vibration, and they need no electrical or air connections, making them immune to fluctuations in line voltage or air pressure. A calibration ring traceable to NIST and international standards comes with the gage and features nominal size at 68°F marked on the face. Calibration checks with the ring ensure that gage-setting capability retains accuracy within original limits of ±0.000020".