The Arm (OEM Part No. 3128309127) is a spare part compatible with Boltec-MC and Boomer-MD underground drilling rigs. Manufactured from high-strength alloy steel, it is designed as a structural component for the arm assembly position in hydraulic and mechanical linkage support systems. The arm provides stable support, connection, and movement control for drilling equipment assemblies, ensuring accurate positioning and reliable operation. Its robust construction withstands heavy loads, vibration, and demanding underground conditions. This OEM replacement arm helps maintain equipment performance, improve operational stability, and extend service life in mining and tunneling applications.