Comparison of internal and external threads pitch diameter measurement by using conventional methods and CMM’s

Abstract

Threads are very frequent and critical connection methods of components to build final products as per desired technical requirements. As it is used for very wide numbers of applications and industries, tolerances and thread structure differ as per requirements of applied areas. After theoretical decision of threaded parts, one hard task is to manufacture this thread as required. Correct flank angle, pitch diameter, pitch, height, major/minor diameters shall be obtained to receive desired mechanical connection properties. So as a result of all importance of threaded connection, it is also important to control thread properties. In this study it is aimed to show that as a result of significant development on sensor and probing technology, Coordinate Measuring Machines (CMMs) are good alternatives of conventional methods by considering accuracy, time requirement, setup requirements, and ease of application. In order to evaluate competence of regular bridge type CMMs regarding simple pitch diameter measurement, results of pitch diameter from symmetric thread with 30º flank angles will be taken by 1D length measurement device and bridge type CMM to compare. Comparison of conventional methods and CMM’s result shows that CMMs also provide accurate and precise results and can be used for calibration of gages as an alternative method with a number of advantages which are shown by this study.