All castings, whether iron, brass, or bronze, are made using sand molds. The quality of the sand is measured by the fineness (size) of the sand particles.
Cast iron is normally manufactured in a range of 40-grain fineness up to about a 75 grain. These grades are used for commercial applications such as motors, pumps, etc.
Architectural castings (literally architectural iron) should have more clarity and “crispness” than can be attained with coarse sands.
We use a 90-grain sand or better to produce clear, crisp detail. While
this costs somewhat more, it gives you, as the fabricator or buyer, a
casting which the architect and owner will rave about, rather than one
which is rejected or which requires extensive (and expensive) clean-up
For more information:
Architectural Iron Company
104 Ironwood Court
Milford, PA 18337-0126
Web Home Page: http://www.architecturaliron.com