Undercutting End Mills, also known as Lollipop End Mills, are specialized milling tools designed for undercutting, deburring, and back-side machining. Their spherical cutting profile allows them to machine features on the underside of a workpiece that cannot be reached with standard end mills. They feature an extended, relieved neck length for clearance between the cutting head and shank, allowing the tool to machine underside features without tool interference.