Sand casting uses a sand mold that is broken after each pour – best for large, complex-geometry iron and aluminum parts at low-to-mid volumes (CT8–CT10 tolerance, ±0.030″–0.060″). Investment (lost wax) casting uses a wax pattern encased in ceramic – best for complex geometries needing fine surface detail and tighter tolerances (CT4–CT6, ±0.005″–0.015″), common in medical, aerospace, and defense. High-pressure die casting (HPDC) forces molten metal into a steel die under pressure best for high-volume thin-wall aluminum and zinc parts (CT5–CT7, ±0.003″–0.010″), common in automotive OEM programs.