Run-out measurement gauge taking external thread as reference

The invention belongs to the technical field of technological equipment measurement, and particularly relates to a run-out measurement gauge taking an external thread as a reference. Comprising a flat plate (2), a supporting plate (5), an adjusting screw (11), a cylindrical end set screw (12), a movable ejector rod (16), a pin flat bushing (30), a positioning seat (21), a movable seat (23), two guide plates (24), a gauge stand seat (26), a supporting block (28), a guide rail (29) and a threaded positioning plate (34), a dial gauge is fixed on the gauge stand seat (26) through a dial gauge stand, and a dial gauge head is in contact with a measuring part of a measured part with proper pressure. The thread part of the detected part is positioned by the thread positioning plate (34) of the detection tool, the detected part is rotated, and the detected part can move in the axial direction and push the gauge stand seat (26) to move synchronously. Synchronous movement of the dial indicator and the measured part is r