STARRETT Telescoping Hole Gage Sets

• Measures the true size of holes, slots and releases from 5/16" to 6".
• The ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gage will enter.
• 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slightly "rocked" in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn.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

Series 229

• Features a handle, one rigid contact arm and one spring-tensioned telescoping contact arm

Series 579

• Similar to the 229 series with a slightly greater range and two telescoping contacts.
• Handles are rigidly attached to the contact plungers and are automatically self-centering.
• Constant spring tension give uniform contact pressure.
• Both plungers are easily locked at any desired setting.