This hardened steel pin is designed as a compatible replacement for OEM part number 0665917001 and is used as a wear component within the rotation head assembly of underground drilling equipment. It is engineered for high strength, wear resistance, and reliable performance under heavy-duty operating conditions. The pin supports precise alignment and consistent torque transmission. Typical applications include M4C rigs, Simba H1354, SIMBA H1254, Boomer 281, Boltec S, and related underground drilling and bolting equipment.