What is an inside dial gage?

An inside dial gage is a compact, easy-to-apply gage for checking the out-of-roundness of connecting rod bearings and holes of shallow depth. Also for inspecting parallelism and for alignment of slots and assembled parts in jig and fixture work. A dial indicator is mounted on top of the base, and on the bottom a positive adjustable slide which is readily set to the approximate hole size or slot width. This slide holds the stationary contact plus two centralizing contacts under spring tension, insuring constant alignment. Bearing surface and contact points are of hardened steel. The contact points are inserted to a depth of approximately 3/8’�?9.5mm).