A rotational tool includes a cutting head and a basic body. The cutting head includes a cutting portion including a chip flute and at least one of a cutting edge and an insert seat, where the chip flute is located before the at least one of the cutting edge and the insert seat in a rotational direction of the cutting head. A coupling portion is located axially rearward of the cutting portion relative to a cutting end of the cutting head, and is configured to couple to the basic body. A coolant slot extends axially and opens at an external radial surface of at least a portion of the cutting head.