These small hole gauges are well balanced tools, ideal for accurately measuring small holes, slots, grooves and recesses in all kinds of work. Accurate measurements are obtained by slightly "rocking" these gauges in the hole to be measured. This will guarantee contact at the true diameter. The final size is then obtained by measuring over the ball contacts with a micrometer.

• Hardened-ball measuring surface with two-point contact.
• Radius on each gauge is less than the minimum diameter to be measured, which provides the two-point contact necessary for maximum accuracy.
• Smooth, sensitive adjustment for better feel, giving more accurate measurements.
• The adjustment of the gauge beyond their range is restricted by a safety stop that prevents breakage.