How do plaster cast parts differ from sand cast parts?
The plaster cast process allows the casting of thin walls (.040″ in aluminum and magnesium and .025″ in zinc). The parts have a very smooth surface finish: 90 RMS for plaster cast parts versus 250 to 500 RMS for sand cast parts. The process allows the casting of complex shapes, providing greater dimensional accuracy that most closely approximates the die cast part.
