What is Tooling (also called wax pattern tooling)?
Investment casting tooling, also called wax pattern tooling, is necessary for all investment castings. This kind of tool is made from high grade aluminum alloys, and designed to allow the flow of molten wax under extreme pressure, in order to allow it to solidify into the wax pattern which is used to form the ceramic mold during the investing process. Unlike sand casting, investment casting tooling replicates the final casting in reverse, due to the fact that we cut “cavities” in which the wax flows to form our patterns. This tooling is often designed to be “collapsible”, in other words, it must be able to be taken apart to remove the solid wax patterns when they have cooled. Another critical element of the tooling design is that the tooling must be constructed so that the wax patterns produced are larger than the final casting dimensions. This is due to the fact that metal shrinks during its solidification, so our engineers must calculate an expected shrinkage rate for every dimension in the tool, and apply those expected shrinkage rates when cutting the tooling. In the pattern tooling, any internal features can be produced, however if the various metal components of the tooling cannot be removed from the wax after solidification has taken place, a suitable method of coring will need to be utilized to form internal features.
Finally, the tooling can consist of simple single cavity varieties or complex multi-cavity tools with automatic ejectors for higher volume jobs.
Due to the required tooling for developing a new investment cast part, at the time of the initial quotation, you will be quoted a piece price cost and a cooling cost. Most foundries will quote tooling as a separate item, same as us. This is usually a onetime cost. It is wise to request that the investment caster describe the type of tooling they are quoting, whether manual, automatic, single or multi-cavity. Tooling is usually considered to be the property of the customer after all outstanding invoices are paid. Tooling is normally stored and maintained in an operational condition by the investment casting foundry. It is critical that the issues of ownership and maintenance be clearly established at the beginning. Normally, the dimensions and structure will determine the tooling cost.
If our steel foundry designed and manufactured the tooling for your project, we will maintain that tooling at no additional charge for the life of the part. If the tooling wears out, breaks, or is otherwise damaged, we will repair and maintain it in ideal working condition for as long as you continue to contract with us for part casting.
To make a casting tooling is the first step to start investment casting process. We’ll make a 3D model as per customer’s drawing or existing samples, with our tooling director’s approval to proceed with tooling or pattern production by CNC mold maker. Usually, the tooling cost will be prepaid with order and we could provide 3-5 samples for customers’ approval prior to placing mass production order. It’s just one-off paid, we’ll not ask for the tooling fee for our future orders, and we’ll repair the tooling or pattern by ourselves if there are any problems of the investment casting tooling. Before the tooling or pattern service in the investment casting process, it will be fully inspected by our QA person.
Besides, it is available to supply our overseas customers with tooling only in a low cost if they would like to make castings themselves. Together with other value added services ( machining, heat treatment, surface finish, ect), our in-house tooling capabilities enable us more competitive than other investment casting suppliers.
Our tooling engineers can work from CAD files in many formats including STEP – Solid, IGES, DFX. Usually, our tooling engineer creates tool paths from a 3 dimensional file and vertical machining centers to make the tooling for your casting. When designing, we should take the proper shrink factor into consideration into the tooling for the alloy that your casting will be poured from. The smoother of the tooling inner surface finish, the better the surface finish of the castings.