A torque-limiting nut is provided. The torque-limiting nut has a washer, a threaded component, and a tool interface. The threaded component has a plurality of detents and the tool interface has a corresponding plurality of recesses and a spring groove. A plurality of engagement members are sized and shaped to fit within the plurality of detents and recesses. An elastic member in the spring grooves provides a compressive force to seat the pins in the corresponding detents to frictionally couple the threaded component and tool interface. When a torque required to rotate the tool interface exceeds a predetermined value, the pin moves against the spring and unseats from the detent such that the tool interface rotates without rotating the threaded component.

An apparatus for a fastening verification structure includes a fastener disposed in a cavity, where a leading end of the fastener is configured to press a non-insulated contact pad. The first end of a first lead electrically coupled to the fastener and a second end of the first lead electrically coupled to a power source. The first end of a second lead electrically coupled to the non-insulated contact pad and a second end of the second lead electrically coupled to a visual indicator. The first end of a third lead electrically coupled to the visual indicator and a second end of the third lead electrically coupled to the power source.

The present invention relates to a method of determining a dimension change of a measurement nut (100), wherein the measurement nut comprises a contact portion (102), adapted for attachment to an object, such as a bolt or a threaded rod, and a non-contact portion (104), the contact portion and the non-contact portion being located coaxially, but axially offset, in relation to each other. The method comprises attaching at least part of the contact portion to the object, the non-contact portion being without direct contact to the object, exposing the object to an external load, thereby causing a dimension change of the contact portion of the measurement nut, and determining the dimension change of the measurement nut by measurement at the non-contact portion. The present invention further relates to a measurement nut (100) and a measurement system (200) comprising the measurement nut.