General description 5Pcs HSS Counterbore End Mill is designed for use with milling machines, making it suitable for high-speed machining of various materials including copper, aluminum, tool steel, and cast iron. These mills are characterized by their high toughness and abrasion resistance, allowing for efficient high-speed cutting, even on high-hardness materials. They can be used for direct processing or fine processing of heat treatment molds, reducing the number of tool changes and improving machine actuator movement rhythm, ultimately saving mold-making time. Technical specifications M3: Blade diameter: 5.9 mm, Boot: 3.2 mm, Shank diameter: 6 mm, Full length: 45 mm M4: Blade diameter: 7.4 mm, Boot: 4.2 mm, Shank diameter: 6 mm, Full length: 48 mm M5: Blade diameter: 9.5 mm, Boot: 5.2 mm, Shank diameter: 6 mm, Full length: 51 mm M6: Blade diameter: 11.0 mm, Boot: 6.2 mm, Shank diameter: 8 mm, Full length: 58 mm M8: Blade diameter: 14.0 mm, Boot: 8.2 mm, Handle diameter: 12 mm,