Typical Shrinkage Allowances for Important Casting Metals
 
Sr.No. Metal Contraction
(per cent) 		Contraction
(mm per metre)
1
Grey cast iron
 0.7 to 1.05 7 to 10.5
2
White cast iron
 2.1 21
3
Malleable iron
1.5 15
4
Steel
 2.0 20
5
Brass
 1.4 14
6
Alluminium
 1.8 18
7
Aluminium alloys
1.3 to 1.6 13 to 16
8
Bronze
 1.05 to 2.1 10.5 to 21
9
Magnesium
 1.8 18
10
Zinc
 2.5 24
11
Manganese steel
2.6 26.5