A self-centering drill assembly includes a drill bit, a chuck adapter, a sleeve, a stop ring, a spring, and a slide ring. The chuck adapter is elongated and includes a first adapter end connected to the drill bit, a second adapter end insertable into a drill chuck, and a shaft connecting the first and second adapter ends. The sleeve includes a first sleeve end slidably mounted on the shaft and a second sleeve end that is tapered and includes an orifice. The stop ring is positioned at the second adapter end. The spring is positioned between the stop ring and an interior surface of the second sleeve end to provide a biasing force to push the sleeve away from the chuck adapter. The slide ring is positioned at the first sleeve end and is configured to guide the sleeve along the shaft and abut against the stop ring.

A self-centering drill assembly includes a drill bit, a chuck adapter, a sleeve, a stop ring, a spring, and a slide ring. The chuck adapter is elongated and includes a first adapter end connected to the drill bit, a second adapter end insertable into a drill chuck, and a shaft connecting the first and second adapter ends. The sleeve includes a first sleeve end slidably mounted on the shaft and a second sleeve end that is tapered and includes an orifice. The stop ring is positioned at the second adapter end. The spring is positioned between the stop ring and an interior surface of the second sleeve end to provide a biasing force to push the sleeve away from the chuck adapter. The slide ring is positioned at the first sleeve end and is configured to guide the sleeve along the shaft and abut against the stop ring.