How does sand casting differ from investment casting?
Sand casting uses a reusable pattern (wood, plastic, or aluminum) to pack sand into a consumable mold, which is broken apart after the metal cools. It is highly cost-effective for large, heavy parts. Investment casting uses a ceramic shell built around a sacrificial wax pattern, offering tighter tolerances (ISO 8062 CT5-CT7), thinner walls (down to 0.040 in), and smooth 125 RMS finishes at a higher unit cost.