CA#400 Quick Change Tool Post 6 PCS Set, CNC Lathe Piston Type, For Lathe Swing 14"-20". The locking mechanism of piston tool post is to push the holder out against the angle gib ways of dovetail by the center hole piston Precision ground and hardened on the piston contact surface and the dovetail to ensure rigidity and repetitive accuracy Advanced design provides built in quick tool changing versatility with positive rigidity to meet the most exacting working tolerances Quickly and easily installed on an engine, bench or turret lathe for a wide range of operations, from fine precise ...