Tightening and Quality Control

Why a Joint Analysis and a PCT (process capability test) of a bolted joint is required for product manufacturers. If you ask in the assembly department whether and how the users check their bolted joints AFTER assembly, there is often astonishment. Especially when already controlled, monitored and regularly tested tightening systems are used. "We assemble with high precision and monitor all parameters. Every year our tools are tested! Why should we still check the joint now? The tools always show correct values." A fallacy and source of quite a few quality defects and recourse claims in connection with bolted joints! In the following, you will find out why the analysis of bolted joints and the random execution of process inspections are so useful, why standards and guidelines specifically require them, and what the technical correlations are.

A tightening tool is a quite complex system – no matter if it is a torque-angle controlled EC-tool or a supposedly easy to use mechanical click wrench. If you look