6.35mm hex shank and includes 2 cutting edges of 10mm, 13mm. The 7-flute chamfered face is sharper and smoother than the 5, three, or single chamfer. The cutting edge is sharp and smooth, high working efficiency. The countersink set is made of good quality high carbon steel which ensures a long service life. Excellent for chamfering, deburring, and countersinking. The seven-flute design allows for small chip loading and faster removal. Can discharge sawdust more quickly and smoothly during use. Suitable for low-hardness boards such as wood, plastic, and other soft materials. Cannot be used for metal. Specifications: Shank Diameter: 6.35mm, Hex Shank. Material: High Carbon Steel. Flute: 7 Flutes. Size: 10mm, 13mm. Usage: It is used for chamfering and drilling wooden boards or thin plastic boards. Suitable for electric drills, bench drills, and other drills. Features: The 7-flute chamfered face is sharper and smoother than sharp-edged chamfers. Recommended for customers who have higher requirements for surface roughness and flatness Chamfered. Industrial Countersink Bit Set Countersink Bit Set for Wood and Plastic. Wood Drill Bit for Woodworking. 7 Flute Carbon Steel Countersink Bit. Wood Drill Bit for Woodworking. Industrial Countersink Drill Bits for Woodworking. Industrial Countersink Bit Set. Note: - Please allow 0-3mm error due to manual measurement, which is normal. - The item is quite sharp, please keep away from children. - Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Contents: Set of 2 Yeuri 7 Flute Countersink Drill Bits (10mm/13mm).Yeuri