A telescopic gauge is a hand-held measuring device which has retractable rods to provide a precise measurement.
It is used by mechanics to measure the size of a bore in an engine. A bore refers to the diameter measurement of the cylinder where the pistons are positioned. For more information, see What is a telescopic gauge used for?
A telescopic gauge has no measurement increments of its own, so it must be used in conjunction with either a micrometer or a vernier calliper.
What telescopic gauge sizes are available?
Telescopic gauges are available in six sizes which are used for holes of different diameters. The size refers to the distance the telescopic rods can measure when they are closed up and then fully extended. The sizes available are: