Tap Test: Evolution of an Old Technique

This special issue on NDT ofadhesive bonds contains papers that discuss a number of issues and approaches for assessing bonded joints. Fundamental to our experience with bonds is the tap test that so many use in their daily lives. In this Back to Basics, the authors review for us the physics of how the tap test works, how technology can improve its capabilities for NDT and how it measures up against other techniques.