This study aims to evaluate the effectiveness of adding CNC parameter monitoring functionality using OPC UA to the existing HMI for CNC grinding machines, specifically focusing on maintaining machining precision for ferrous materials despite changes in grinding wheel diameter post-dressing. Three workpieces, each ground with different wheel diameters (WD162.24, WD162.22, WD162.20), were subjected to profile error measurements at various angles within a ±4.0μm tolerance range. The elliptical shape of the workpieces required diameter measurements across a 90-degree section. Results indicated that, despite slight deviations, all workpieces remained within the specified tolerance range, demonstrating that the OPC UA-based monitoring system effectively maintains machining precision after wheel dressing. This suggests significant potential for improving grinding processes for ferrous materials using OPC UA-integrated CNC systems.