Which materials work best for low-volume sand casting?

Aluminum Alloys for Lightweight and General Application

For low-volume sand casting, aluminum alloys are often the top choice due to their excellent castability, good strength-to-weight ratio, and corrosion resistance. Alloys like A356 are superb for their combination of strength, ductility, and pressure tightness, making them ideal for structural and automotive components. A360 offers superior pressure tightness and higher strength than many other aluminum casting alloys, though with slightly lower ductility. For general-purpose applications where excellent fluidity and machinability are key, A380 is a widely used and cost-effective option.

Cast Iron for Strength and Wear Resistance

When the application demands high strength, excellent wear resistance, and superior vibration damping, cast iron is the go-to material for low-volume sand casting. Gray Iron is one of the most common choices for engine blocks, pump housings, and machinery bases due to its compressive strength and good machinability. Its ability to be cast into complex shapes makes it perfectly suited for the design flexibility of Sand Casting.

Copper-Based Alloys for Specialized Properties

For components that require high corrosion resistance, excellent bearing properties, or good thermal conductivity, copper-based alloys are unmatched. Aluminum Bronze C95400 offers high strength and outstanding resistance to wear and corrosion, ideal for gears, valves, and marine hardware. Other alloys, such as brass and Tin Bronze, are also frequently chosen for low-volume runs of plumbing fixtures, bearings, and architectural elements.

Carbon and Low-Alloy Steels for High Strength

For the most demanding applications requiring high tensile strength, toughness, and impact resistance, carbon and low-alloy steels are the best performers. These materials are essential for structural components in heavy machinery, mining equipment, and defense. While they present more challenges in casting, such as higher pouring temperatures and a greater risk of defects, the sand casting process is well-suited to manage these requirements for small batches where the superior mechanical properties are non-negotiable.