The Starrett 711EA universal friction holder with shank is used to mount Starrett 711 series dial test indicators (not included) for taking precise measurements. A ball joint provides flexibility in positioning. The friction holder has a 3/16" (4.8 mm) diameter shaft for mounting in chucks and Starrett 57 and 257 series surface gauges.
Test indicator gauges, also called gages, are precision instruments that measure short linear distances. They are commonly used for detecting deviations from tolerance limits, such as small variations in flatness or height of an inspected workpiece, and permit measurement in narrow grooves or small bores. A test indicator gauge consists of a ball-tipped contact point on a levered arm, also called a measuring insert, which pivots from a hinge point. The reading indicates the degree of angular displacement of the arm. Test indicator gauges are commonly used in manufacturing, machining, and mechanical engineering. Standard test indicators measure the displacement of the arm perpendicular to the axis of the indicator. Dial and electronic indicators are very similar to test indicators, except that the axis of measurement is parallel to the axis of the indicator. Test indicators can be analog, with a mechanical dial, or electronic, with a digital display. Some electronic models transfer the data electronically to a computer for recording and potential manipulation.
The L.S. Starrett Company manufactures precision measuring tools, metrology and testing equipment, and saw blade products. The company, founded in 1880, is headquartered in Athol, MA.
