Investment castings

Steel investment castings and stainless steel investment castings are the most common. But investment castings can also be made with aluminum and brass alloys. The investment casting process will produce near net shape components with a high "as cast" finish (RMS 60 to 200) and tight tolerances (0.005"), thereby providing a visually attractive part that will need very little sceondary machining to complete.

Investment casting involves an expendable pattern, typically made by injecting wax or plastic into a metal mold. The pattern is then coated with a refractory slurry that will set at ambient temperature to produce a mold or shell. The shell is then turned upside down and the expendable wax or plastic is melted out. To complete the refractory shell, ceramic cores may be inserted for additional details. The steel or stainless steel alloy is poured into the shell, creating the components intricate shape.