When inspecting the diameter of the edge break, what part of the countersink gauge should contact the assembly surface?

The setting ring of the countersink gauge is designed to make contact with the assembly surface during the inspection of the diameter of the edge break. Its purpose is to provide a reference point when measuring the countersink, ensuring an accurate assessment of the edge break dimensions. When the setting ring is in proper contact with the assembly surface, it stabilizes the gauge, allowing the probe tip to be correctly positioned for measuring the diameter. This ensures that any readings taken reflect the true dimensions of the countersink feature, contributing to the quality and safety of the assembly.

In contrast, the probe tip is typically used to take the actual measurement, but without the setting ring in contact with the surface, the accuracy of that measurement could be compromised. The measurement scale is merely a visual reference for reading measurements and does not provide any contact or guidance during the inspection process. The base plate, while providing stability to the gauge, does not interact directly with the assembly surface in the context of measuring the edge break diameter. Thus, the setting ring's role is critical for ensuring the proper measurement protocol is followed during the quality inspection process.