An MVD tungsten carbide treatment increases the life of thermowells and protection tubes. The tungsten carbide is fused with the thermowell material and becomes an integral part of the mass of the well, resulting in a substantially harder and more durable application. The treatment is specially designed for applications in highly abrasive/erosive environments where the temperature range is ambient to 1800°F. It is capable of withstanding temperatures up to 2300°F.