Starrett 579 Series Telescoping Gage 1/2-3/4"/13-19mm w/8"/200mm Handle

The Starrett Telescoping Gages are used for determining the true size of holes, slots and recesses up to 6"/150 mm. The ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gage will enter. These tools must slightly "rocked" in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn. Handles are rigidly attached to the contact plungers and are automatically self-centering. The final hole size is obtained by measuring over the gage contacts with a micrometer. This model, 579B-8 has a measuring Range of 1/2 to 3/4" / 13 to 19 mm with an 8" / 200 mm Handle.