Each of the three molding methods has relative
capabilities, advantages, and costs, as shown in the table below. |
|
Target |
Shell-Mold |
Air-Set Sand |
Green Sand |
As-cast dimensional
tolerance across 1" |
+/-
0.060 |
+/- 0.030 |
+/- 0.060 |
+/- 0.060 |
Nominal surface finish
(RMS) |
500-900 |
300-500 |
500-900 |
500-900 |
Minimum Section
Thickness |
0.50
inch |
0.25 inch |
0.25 inch |
0.25 inch |
Intricacy of detail |
Fair |
Very Good |
Good |
Fair |
Tool/Pattern Cost |
Low |
High |
Low |
Low |
Mold Material Cost |
Low |
Medium |
Medium |
Low |
Tool Lead Time |
Short |
Long |
Short |
Short |
|
Given the as-cast
tolerance and finish requirements, the level of detail, and the low cost driver for the
insert plates, choose an appropriate molding method --
SHELL MOLD, AIR-SET
SAND, GREEN
SAND |
|