• Gray cast iron (small and medium castings) 1%
• medium and large: 0.9%
• High-strength cast iron 1~1.5%,
• Nodular cast iron 1%,
• Tin bronze 1.4%,
• Wuxi bronze 2～2.2%
• Aluminum silicon alloy 1～1.2%

The above are all linear shrinkage rates (free shrinkage)

Shrinkage rate of sand casting of various metal materials: This problem is too big. For cast steel, there are: 1) Alloy: carbon steel, stainless steel, alloy steel; 2) Carbon content: low carbon steel, medium carbon steel, High-carbon steel; three) molding sand: green sand, surface dry sand, dry sand, sodium silicate sand, resin sand; four) shrinkage: body shrinkage, linear shrinkage; five) casting shape: large simple parts, Large complex parts, medium simple parts, medium complex parts, small simple parts, small complex parts. The same goes for cast aluminum, cast iron, and cast copper.