The same containing cobalt high speed steel material, the surface after a TiAIN coating, 3 times can prolong service life. The TiAIN coating super high temperature , can be in the case of without coolant, long time use, suitable for dry type high speed cutting. Industrial Grade TiALN Coating,TiAlN coating surface will form Al2O3 which form a hard protective layer when drilling.(Perfect for high speed drilling) HSS - CO high speed steel after heat treatment + TiAIN coating surface hardness up to 89 degrees. TiAIN coating can do not need to add cooling fluid, more suitable for aerial work where the work is not convenient to add cooling water systems. 90 degree chamfer, CNC CNC, CBN grinding process. Higher accuracy sharper achieve drilling burr. Internal chip removal: To eliminate the phenomenon of flying metal shavings. Hardness: HRC89 Size: 1/4inch Hex Uses: High-speed steel cobalt / M35 TiAIN coating (Suitable for Aluminum, insulation board, PVC board chamfer,steel, aluminum, sheet metal, carbon steel, 304 stainless steel, etc.) - Industrial-grade TiAIN coating (More than 4241and 6542 high-speed steel materials, live longer!) Colour: silver Material: high-speed steel cobalt Size: 2-5mm Package Contents: 1 * Countersink Deburring Bit Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.