A pneumatic rotary tool including a housing having an inlet passage. The inlet passage extends from an inlet operatively connectable to an air source. The inlet passage extends to a motor cylinder inside the housing. The housing has an outlet passage extending from the motor cylinder to an outlet. The tool includes a rotor mounted in the cylinder for rotation relative to the cylinder under pneumatic power. The tool includes a valve positioned along the inlet passage operable to selectively permit air to pass for rotating the rotor and flowing through the outlet. The tool has a cutter head connected to the rotor including a clamp for holding a cutter to cut material as the head rotates. The cutter head is positioned in the outlet so air passing through the outlet passes over the head to blow material away from the head as the cutter cuts the material.