Tooling is one of the key fixed costs for shell mold casting process. The foundry is responsible for designing the tooling, and the customer often maintains their ownership.
The tooling is normally including the patterns, core boxes, machining fixture and other tooling elements. Shell mold casting tooling's price is affected by the following factors.
One major factor that affects tooling costs is volume. In cases of especially large volume, tooling will need to undergo periodic maintenance or even replacement. Typical iron pattern tooling will last approximately 300,000 impressions, while iron core boxes can reach approximately 250,000 shots. Steel patterns and core boxes can last nearly twice as long, often exceeding 500,000 impressions or shots. While it lasts longer, steel tooling is more expensive to produce.
As patterns and core boxes approach the end of their useful life spans, chances of producing off-dimension parts increases. Aging patterns and core boxes sometimes also contain dings and scratches resulting from repeated sand coatings, and the abrasion also gradually roughens the surface finish. If gating components are worn but the pattern plate or core box is still fully functional, the gating can simply be replaced. The same applies to pattern inserts and ejector pins. However, foundries will often advise customers to replace the pattern or core box before surface finish or dimensional accuracy is affected by wear.
Other factors that affect the cost of tooling size, number of core boxes, number of plate cavities, number of gate contacts and the number of pattern inserts. All of these characteristics of tooling determine the overall degree of complexity of the project. The higher the complexity, the higher the cost.