CarTech 420F stainless is easy to machine, grind and polish, and has certain nongalling or nonseizing properties in service. It has been used for parts made on automatic screw machines, such as valve trim, pump shafts, needle valves, ball check valves, gears, cams, pivots, etc. This free-machining hardenable steel has been used mainly for machined parts requiring high hardness and good corrosion resistance. It is not recommended for vessels containing gases or liquids under high pressure. CarTech 420F and other free-machining stainless steels are not recommended for plastic mold cavities where a high mirror finish is essential.