Which casting method uses a wax pattern, a refractory slurry around it, dewaxing, pouring metal, and destroying the shell to release the part?

• A. Investment Casting
• B. Die Casting
• C. Sand Casting
• D. Shell Casting

Answer: (A)

Investment casting, also known as lost-wax casting, uses a wax pattern that is coated with a refractory slurry to form a ceramic shell. Once the shell is built and cured, the wax is melted out in a dewaxing step, leaving a hollow mold. Molten metal is then poured into this mold, and after it solidifies, the ceramic shell is broken away to release the final part. This exact sequence—wax pattern, ceramic investment, dewaxing, metal pour, and shell destruction—is what defines this method. The other processes use different mold-making approaches (for example, die casting uses a permanent metal mold with high-pressure injection; sand casting uses a sand mold around a pattern; shell casting involves a thin ceramic shell but not the dewaxed wax pattern approach described here).