Solid Carbide End Mill 16mm 16R1x55-66x110xD16D1 (Cutting diameter): 16mm D3 (Undercut diameter): 15. 4mm L2 ( Length of cut): 55mm L3 (Length of undercut): 66mm L1 (Total length): 110mm D2 (Shank diameter): 16mm Z (Number of cutting edges): 4 R Corner radius: 1mm Helical pitch: 38 Special aerospace geometry optimized for vibration free milling and ideal chip removal for thin walled workpieces and complex internal machining Radius tolerance r 1. 5 mm: 0. 003 mm Radius tolerance r > 1. 5 mm: 0.