: In casting components, Non-destructive testing (NDT) techniques are widely used to detect and characterize internal flaws. Among various inspection methods, ultrasonic testing (UT) offers high sensitivity to internal discontinuities and provides a safer alternative to radiographic testing. This research investigates the influence of key parameters such as surface preparation, probe frequency, signal interpretation, and material density on flaw detection accuracy. Advanced UT approaches were employed to generate flaw mapping across different materials, where multi-probe scanning demonstrated improved accuracy, efficiency, and suitability for complex geometries. Synthetic Aperture Focusing Technique (SAFT) images were reconstructed from A-scan ultrasonic data to enhance defect visualization. SAFT enables post-processing beam focusing at each image point, leading to improved spatial resolution and clearer identification of internal defects. The results confirm that optimized UT parameters combined with SAFT imaging significantly improve reliability, defect localization, and overall quality assessment of casting components.