FIX-3.5-20 is an industrial-grade fastening system designed for high-temperature applications. The system is composed of a fastening screw, a hexagon-shaped locking nut, and a nylon-inserted lock. This system is designed to withstand high temperatures up to 350°C (662°F) and is commonly used in automotive and aircraft engine components, as well as other components such as exhaust manifolds, intake manifolds, and exhaust headers. Additionally, the system is highly resistant to corrosion, as well as shock, vibration, and thermal shocks.