Discover the AT3 BT Tool Holder BT50 Shell End Mill Arbor with HRC55 hardness, designed for precision milling. This high-precision tool holder features AT3 accuracy, ensuring maximum spindle contact. Ideal for axial or radial drive grooves, it supports various milling cutters like face mills and vertical disc cutters. Pre-balanced for G6.3 or G2.5, it offers exceptional performance up to 8,000 rpm.