Size: Fits hand drills and electric drills with 1/4 shank (6.35 mm). Cutting diameter length: 8/9.5/12.7 mm. Application: These 1/4 shank router bits are suitable for solid wood panels, MDF, particleboard, and design profiles, for smooth, detailed cuts and for creating stylish furniture. They are also suitable for routing grooves in frames, panels, clocks, towers, and other wall tools, for making keyhole hooks or cable ducts. Features: The carbide blades are high-quality welded to ensure stable quality and high performance, and you don't have to worry about breakage or tilting during work. The blade is sharp and durable, and features a rounded curve design that is good for broaching and more efficient for striking.