BT shell mill arbors Combination shell end mill arbors. For CNC milling machine,G6.3 8000-12000r/min.G2.5 ... 12000-20000r/min. BT shell mill arbors,combination shell end ... mill arbors.For CNC milling machine,G6.3 8000-12000r/min ... -32-100 58 69.85 4.70 BT Shell mill arbor,combination shell end mill arbor