Starrett 229 Series Telescoping Gage 1/2-3/4"/13-19mm w/2-3/8"w-60mm Handle

The Starrett Telescoping Gages are used for determining the true size of holes, slots and recesses up to 6"/150mm. Features a handle, one rigid contact arm and one spring-tensioned telescoping contact arm. 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slightly "rocked" in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn. The final hole size is obtained by measuring over the gage contacts with a micrometer. This model, 229A has a measuring Range of 1/2 to 3/4" / 13 to 19mm with a 2-3/8" / 60mm Handle.