Measurement device for automotive steering system nuts: As a key connecting component, the thread accuracy and reference position of the automotive steering system nut directly determine the assembly quality and driving safety of the steering mechanism. The traditional measurement method relies on manual sampling and a single measuring tool, which makes it difficult to simultaneously meet the dual requirements of diameter accuracy and spiral reference position, and cannot meet the strict standards for stability and consistency in mass production. This device is designed specifically for automotive steering system nuts, achieving synchronous and precise measurement of the OBD center diameter and spiral reference position. Through standard part calibration, repeatability verification, and on-site testing, the entire process is closed-loop