Starrett S830FZ Small Hole Gage, Set of 5, .125" to .500" (3.2mm to 12.7mm)

Radius on each gauges is less than the minimum diameter to be measured, which provides the two-point contact necessary for maximum accuracy

The set includes ranging from 0.125"-0.150", 0.150"-0.200", 0.200"-0.300", 0.300"-0.400" and 0.400"-0.500" and length 2", 5 gauges in set

These small hole gauges are well balanced tools that are ideal for accurately measuring small holes, slots, grooves, and recesses in all kinds of work. Accurate measurements are obtained by slightly "rocking" these gauge 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.
Brand: Starrett, Model: S830FZ