In a previous GCG Perspective, castings were highlighted as a hidden bottleneck in the Aerospace and Defense supply chain.

Not all castings are created equal, however. In aerospace and defense, selecting the appropriate casting process is a critical engineering decision that influences a component’s strength, dimensional accuracy, weight, material performance, production cost, and long-term reliability. While investment casting, die casting, and sand casting all transform molten metal into finished components, each process serves a distinct purpose based on part complexity, production volume, size, and material selection.

Investment casting, commonly referred to as lost-wax casting, is the preferred process for highly engineered, mission-critical components with complex geometries and demanding material requirements. The process begins with a wax replica of the finished part, which is repeatedly coated in ceramic to create a precision mold. Once the wax is melted away, molten metal is poured into the ceramic cavity to produce a near-net-shape component with exceptional dimensional accuracy and surface finish.

One of investment casting’s greatest advantages is its ability to process virtually any engineering alloy, including stainless steels, titanium, cobalt alloys, and nickel-based superalloys. These materials have significantly higher melting temperatures than aluminum or zinc. Steel melts at approximately 2,500-2,800°F, while titanium melts near 3,000°F, making them unsuitable for conventional die casting. Investment casting is therefore widely used for turbine blades, aircraft structural fittings, missile components, valve bodies, landing gear hardware, and other parts where intricate geometries, superior mechanical properties, and high-temperature performance are essential.

An M&A example within investment casting would be Arcline’s 2025 investment into American Casting Company.

By contrast, die casting is engineered for high-volume production of precision components. Molten metal is injected into hardened steel dies under extremely high pressure, allowing manufacturers to produce thousands – or even millions – of identical parts with excellent repeatability, tight tolerances, and outstanding surface finishes.

The process is largely limited to aluminum, zinc, and magnesium alloys for a good reason. Zinc melts at only 787°F, while aluminum melts at approximately 1,220°F. These relatively low melting temperatures allow hardened steel dies to survive repeated thermal cycling without excessive cracking, erosion, or wear. Attempting to inject molten steel or titanium into the same tooling would dramatically shorten die life and make the process economically impractical.

Equally important is the exceptional fluidity of molten aluminum and zinc. Under high injection pressures, these alloys readily fill extremely thin walls, complex ribs, intricate bosses, and detailed features before solidifying. This combination of low melting temperature and excellent flow characteristics makes die casting ideal for lightweight structural housings, electronic enclosures, actuator bodies, gearbox cases, UAV components, and other high-volume aerospace and defense applications where dimensional consistency is paramount.

An M&A example within die casting would be ADC Aerospace’s 2026 acquisition of Hyatt Die Cast & Engineering Company. ADC is a portfolio company of GreyLion.

Sand casting occupies a different niche altogether. Rather than relying on permanent tooling, molds are formed from compacted sand around a reusable pattern and destroyed after each casting. Because tooling costs are relatively low, sand casting is particularly well suited for prototypes, low-volume production, replacement parts, and very large components.

Like investment casting, sand casting accommodates virtually any casting alloy, including steel, iron, aluminum, bronze, and numerous specialty materials. Its primary advantage lies in flexibility rather than precision. Large gearbox housings, naval propulsion components, pump bodies, engine cases, armored vehicle castings, and structural supports are frequently manufactured using sand casting because the process can economically produce components weighing hundreds or thousands of pounds. The tradeoff is lower dimensional accuracy and rougher surface finishes, requiring additional machining to achieve final tolerances.

As an M&A example within sand casting, Greenwich Capital Group advised on the 2025 sale of Bay Cast Inc. and Bay Cast Technologies, a premier provider of large, complex steel castings and machining solutions. More information on that transaction can be found here.

Ultimately, each casting process occupies a distinct position within aerospace and defense manufacturing. Investment casting excels when complex geometries, advanced alloys, and mission-critical performance are required. Die casting delivers unmatched productivity and precision for high-volume aluminum, magnesium, and zinc components, benefiting from the low melting temperatures and excellent fluidity of these alloys. Sand casting remains the most versatile solution for large, lower-volume components and difficult-to-cast alloys where tooling costs and material flexibility are primary considerations.

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