Because a thin permeable refractory shell is applied around the smooth foam pattern, the resultant finish is excellent. (See comparison on chart). Each casting facility may differ slightly from standards shown. This must be discussed and agreed upon based on the function and cosmetic requirements of the part prior to release of the tooling order.
CASTING PROCESS______RMS RANGE
Die Casting ----------------------20-120
Investment Casting ------------60 - 200
Lost Foam ------------------------60 - 250
Shell Mold ------------------------120 - 300
Centrifugal - Perm. Mold -----120 - 300
Static - Perm ---------------------200 - 420
Normal Non-Ferrous Sand ---300 - 560
Normal Ferrous Green Sand -560 - 900