Feature●For penetrating holes in wood●Size D: 0.4 inches (10.0 mm), Total Length: 4.3 inches (110 mm), Groove Length: 2.4 inches (60 mm), Chuck Diameter: 0.6 inches (6.35 mm)●Compatible models: Electric drill (0.2 inch (6.5 mm) chuck diameter 0.8 inch (21 mm), can be used up to 0.4 inch (10 mm) chuck diameter 1.2 inch (30 mm), 0.5 inch (13 mm) chuck diameter 2.0 inch (50 mm); Impact driver (0.8 inch (212 mm) or higher)●Because it uses special alloy steel, it has less wear and can be used for a longer time●It is easy to eat on processed materials and cuts wood shavings well, so you can perform efficient work●Please use the electric tool with a rotation speed of 3,000 or lessDescription ● Ideal for drilling boards and boards. For use with an impact driver (12 V or above), the pitch of the retraction screw is fine, and the screw thread is reduced to reduce resistance and allow for drilling holes up to 0.8 inches (21 mm). The hexagonal shaft (0.25 inch (6.35 mm) has two ball grooves, making it compatible with both manual handles and impact drivers.