Snappy Tools 5 Pc. Countersink Set allows you to drill the pilot hole and countersink or counterbore for screws in one easy step. The 82° countersink is designed to match the angle on the head of most screws, ensuring a fit every time. Precision machined in the USA with tight tolerances, this set is made of thru-hardened alloy steel that provides long cutting life. Featuring a 1/4" hex power bit shank, it fits in impact drivers and quick change chucks for versatile use. The drill bit can be easily adjusted or replaced by loosening the hardened set screw, which s a secure hold on the pilot drill. For precise depth control, you can utilize the Snappy Premium Rotating Depth Stop (Part # 43032), sold separately.