This hardened steel pin is designed as a compatible replacement for OEM part number 0665910016 and functions as a wear part in the rotation head assembly of underground drilling and bolting equipment. Built to handle high load and vibration, it helps maintain precise alignment and stable rotation during drilling operations. The pin is suitable for a wide range of machines including M4C series rigs, Boomer L2D, Simba H1354, ROC-D7-11, ROC-D9-11, and related underground drilling applications.