Counterbore Endmill M3.2-M12.4

This product is a set of HSS (High-Speed Steel) Counterbore End Mill Cutters, specifically designed for precision machining in a milling machine. Each bit features a unique pilot tip that guides the tool into a pre-drilled hole, allowing the four-flute cutter to create a perfectly aligned, flat-bottomed recess (a counterbore). These are essential for seating bolt or screw heads flush with a surface and are durable enough to cut through materials like aluminum, steel, and cast iron.