Indicating Gages also called dial gages, indicating gages are available for checking almost any dimension imaginable . Their primary functions are usually expressed by their names.
For example , standard dial bore gages, are available to check bore diameters ranging from 0.37 to 12.13 in.(9.5 to 308.0mm) .Midget versions are also available to check much smaller bores.
Standard anvil and blade anvil dial snap gages , are available to check O. D.s and grooves up to 18 in. (450mm) in diameter.
Dial depth gages are supplied with an assortment of extensions and contact points to permit checking depths ranging from 0 to 3 in. (0 to 75mm)
Bench comparators , are widely used by production and inspection department to check diameters , lengths , thicknesses , and other similar dimensions . Many styles are available , with ranges to 8 in.(200mm).
Indicators are normally graduated in 0.0001 in., 0.00025 mm depending on the range of measurement and discrimination desired.
The indicating gages shown are only a few of the many differentt style that are available today. Process and tool engineers concerned with gaging short production runs should keep abreast of the many standard models that are available.
One of the drawbacks to using indicating type gages is the fact that most of them must be set and constantly compared with a calibrated master gage (mastered) such as a setting ring, setting disc, or depth master, Master gages can be relatively expensive for larger diameters and also have long lead times which should be taken into account when planning for limited production . There are , however, universal type masters which are practical for short runs.
The preferred method of setting and mastering shallow diameter gages. Whether for short run or for high production , is with an adjustable shallow diameter reference master. Most shallow diameter gage users set the gage to a standard length measurement device, such as a set of gage blocks , and then use the gage to set the reference master.