A method of quantifying stem nut thread wear in a valve having a valve stem that is positioned with a stem nut. A tool is mounted to, and rotates with, the stem nut, while simultaneously measuring stem displacement. The method of orienting the stem nut threads where one 360 rotation will capture all of the thread backlash in addition to any stem displacement. The measured stem displacement, including stem nut thread backlash, can then be used, with certain stem geometry parameters, to calculate stem nut thread wear percent and quantify remaining stem nut thread material.

A method and apparatus for measuring stem nut wear in a valve having a threaded valve stem that is positioned to engage the threads of a stem nut. In a preferred embodiment, a tool is mounted on the stem nut, wherein the tool rotates when the stem nut rotates. The tool indicates a measurement of stem nut rotation. An indicator indicates stem movement. The stem nut is rotated and the amount of percent wear is observed. Rotation continues until the stem begins to move. The tool provides a reading when the stem begins to move that indicates an amount of stem nut wear.

A screw thread measurement system and methods may comprise a frame having a reference surface, a carrier coupled to the frame and configured to translate relative to the frame, a dimension measurement system coupled to the carrier and having a thread contact element configured to translate relative to the frame and orthogonally the translation axis of the carrier. The dimension measurement system configured to determine thread dimensions relative to the frame reference surface.

A device for identifying bolts and nuts can include a plurality of threaded bodies, wherein each threaded body of the plurality of threaded bodies includes: a female threaded portion; and a male threaded portion, the male threaded portion being connected to the female threaded portion; wherein the female threaded portion and the male threaded portion extend in opposite directions; a flexible connector including a plurality of flexible portions that connect the plurality of threaded bodies; wherein each flexible portion of the plurality of flexible portions has a height, a width and a length, the length being larger than the width, and the height being larger than the width so that the flexible connector is more flexible along a first plane than a second plane perpendicular to the first plane.