Selecting a Countersink Gauge on Amazon.com
A countersink gage, or countersink gauge, has a conical plunger that measures the largest diameter of a countersunk hole, and a dial indicator that displays readings in either hundredths of a millimeter or thousandths of an inch. It is sometimes called a countersink depth gauge because its reading is based on how far the plunger extends into a hole, but it is diameter rather than depth that is actually being measured. Each gage is designed for a specific angle, and countersink gauges are available for 82-, 90-, 100-, 110-, and 120-degree angles. Inch gauges have a white dial face and measure in ranges between 0.160" and 1.180". Metric gauges have a yellow dial face and measure in ranges between 0.5 mm and 19.8 mm. A countersink gage should be calibrated against a part master that has the specified countersink angle. It is commonly used in carpentry, manufacturing, machining, and mechanical engineering.