Quench Polish Quench

Stucchi Glossary

Quench polish quench (QPQ) is a specialized type of nitrocarburizing case hardening that increases corrosion resistance. It is sometimes known by the brand name of Tufftride, Tenifer or Melonite.[1] Three steps are involved: nitrocarburize (“quench”), polish, and post-oxidize (“quench”).

Source: Wikipedia