Gauge Wheels are used to check thickness.
Gauge Wheel Size is measured inside the holes. Measures from 18 Gauge to 1-Inch Made in China. Not practical to use. #PT202
Size is measured between the outer flanges, not by the hole.
Gauge Wheel Place jewelry between the flanges along the outer edge, not in the hole. Measures from 0 Gauge to 30 Gauge Made in India #PT201
How to use GAUGE WHEELS. What do the numbers mean? What is AWG?
Plastic Caliper