Average Shrinkage of Metal Castings

These average shrinkage figures are for metals cast with

uniform sections under normal conditions. When using

these figures, it should be remembered that the size and

the shape of the casting must be considered, since thick

castings have less shrink and thin castings have more

shrink than indicated by the figures given in the table

below.

                               Typical Shrinkage

Metal                                                        (Inches per foot)

Cast Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/10

Ductile Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/10

Malleable Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/10

Steel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/16 or 1/4

Brass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3/16

Copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/16

Aluminum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/8 or 5/32

Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5/16

Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5/16