Feature: 1. High Hardness: Carbide cutter head, possess high hardness, wear resistance and heat resistance, and long service life 2. Meet A Variety of Work Needs: The package contain files with single and double slot design to meet a variety of work needs 3. Chip Removal: file drill bit set come with high working efficiency and chip removal, very practical 4. Single Slot For Harder Materials: Single slot is suitable for harder materials such as iron, steel, copper, etc. which is labour saving 5. Double Groove For Softer Materials: Double groove is suitable for softer materials such as wood, aluminum and plastic, with high efficiency Specification: Item Type: File Material: Carbide Surface Treatment: Single and double pattern Ti plating Product Ratio: Cemented carbide file Shank Diameter: Approx. 3mm / 0.12in Hole Position: Approx. 3mm / 0.12in Length: Approx. 38mm / 1.5in Package List: 20 x File