Valve stem screw. A Screw that is used to secure the Tire Pressure Monitoring Sensor to its mounting point. A Screw used to secure the Tire Pressure Sensor Valve stem. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Tire Pressure Monitor Sensor Valve Stem to its mounting surface. Pressure Monitoring (TPMS) Stem Bolt. TPMS Sensor. Included with: Valve stem.