The Starrett® 229 telescoping gage is used for determining the true size of holes, slots and recesses upto 6 in. The ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gage will enter. This tool must be slightly "rocked" in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn.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.

Starrett® Telescoping Gage, Series: 229, 1/2 to 3/4 in Measuring, Rigid Handle, Polished Chrome, 3-3/16 in L x 5/16 in W x 49/64 in H Dimensions

• Ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gage will enter
• Precision ground radius on each gage provides two-point contact for maximum accuracy
• Handles can be individually ordered and/or ordered in larger sizes such as 8 in, 12 in or longer
• Features a handle, one rigid contact arm and one spring-tensioned telescoping contact arm

• https://externalassets.unilogcorp.com/ASSETS/DOCUMENTS/ITEMS/EN/Starrett_229A_Full_Engineering_Drawing.pdf https://externalassets.unilogcorp.com/ASSETS/DOCUMENTS/ITEMS/EN/Starrett_229A_Full_Engineering_Drawing.pdf