The Fraser Drum Gauge. Easily, the industry standard for the accurate measurement of scored, worn, or heat-checked brake drums.
Easy reading 4” dial calibrated in ten thousandths from MINUS .040 to PLUS .120. Measures any brake drum from 12” to 18” diameter in ¼” increments.
Determine the diameter of the drum to be tested
Set the gauge to the correct size
Loosen the side screw
Extend shaft to desired length
Tighten screw to secure the proper position
Place the gauge inside the drum moving up and down the entire length of the drum testing for groves or excessive wear