In this study, we present the development of a diametrical OCT system utilizing two scan heads to improve the depth measurement range for the visualization of thick samples. To ensure accurate imaging, a novel alignment method was developed to manually align both scan heads. For precise calibration of the system, a calibration target was utilized in conjunction with a developed calibration algorithm. This approach facilitated fine adjustments of the merged data sets. The calibration algorithm accounted for any potential misalignment or discrepancies in the optical setup, thus improving the accuracy and reliability of the system. A stack of glass cover slips with a thickness of 4 mm and a double aspheric lens with a center thickness of 4.5 mm were imaged to test the calibration method and the overall system. The system demonstrated the capability to effectively visualize and provide high-resolution cross-sectional images of such thick samples, showcasing its potential for applications in the quality assurance of technical samples.