2015-18. Valve screw. A Screw that is used to secure the Tire Pressure Monitoring Sensor to its mounting point. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Tire Pressure Monitoring Sensor to its mounting surface. stem fastener. stem retainer. FASTENING 5X13. Hexagon socket head. Tire Pressure Monitoring System (TPMS). Included with: Pressure Sensor, Valve.