Reaming and deburring lines allows for the best possible flaring and joining of tubing without the risk of metal shards contaminating the job! This inside/outside reaming and deburring tool works with 3/16″ (4mm) through 1/2” (14mm) O.D. steel, copper, copper-alloy, & aluminum tubing. Perfect for brake, fuel, transmission, and coolant lines. Jaws and blades are formed from high-strength steel and are retractable into the billet steel body for safety. Three cutting edges ensure clean, even deburring every time.