permanent mold process employs gravity pouring of metals using steel,
or graphite molds. The castings produced have excellent grain structure
and extremely low porosity which result in superior ductility and outstanding
strength. The castings can be designed with thinner walls and less weight
with good dimensional accuracy. Used primarily for low melting temperature
metals such as aluminum & zinc, permanent mold castings produce excellent
finishes & pressure tightness when compared to sand castings.
Savings in reduced machining operations can also be realized due to the dimensional uniformity of the castings and details that can be cast in, as well as reducing some secondary operations such as polishing due to the excellent surface finish. Permanent molds have a production life of 10,000-40,000 parts, casting sizes range from a few ounces to 50lbs.