With a hex shaft (0.25 inch (6.35 mm) finish, it can be attached to an impact driver with one touch, making it easy to use as an iron work drill. The X-shaped thinning process provides good adhesion and the tip of the shavings can be discharged easily, thus extending the life of the drill. It also does not require a center punch. (0.08 inch (2 mm) or higher) The drill blade uses Nachi drill. The hexagonal shaft and drill are completely glued, but the pin is included to prevent it from rolling and falling out, so you can use it with confidence.