A bond strength tester unit is provided for testing adhesive bond strength of a nutplate or the like attached to a substrate, such as by adhesive bonded attachment to a blind side of the substrate in substantial alignment with a substrate opening. The nutplate may be constructed according to U.S. Pat. No. 5,013,391, and carries a fastener element such as a threaded nut or the like for subsequent connection with a mating fastener element such as a threaded bolt or the like passed through the substrate opening. The tester unit includes a tool tip having a reaction head for engaging the substrate, in combination with an actuator pin for applying a test force of selected magnitude against the adhesively bonded nutplate. In the event of inadequate bond strength, the actuator pin will separate the nutplate from the substrate.