Comparative qualities of cast irons^[1]

Name

Nominal composition [% by weight]

Form and condition

Yield strength [ksi (0.2% offset)]

Tensile strength [ksi]

Elongation [% (in 2 inches)]

Hardness [Brinell scale]

Uses

Cast grey iron (ASTM A48)

C 3.4, Si 1.8, Mn 0.5

Cast

—

25

0.5

180

Engine blocks, fly-wheels, gears, machine-tool bases

White

C 3.4, Si 0.7, Mn 0.6

Cast (as cast)

—

25

0

450

Bearing surfaces

Malleable iron (ASTM A47)

C 2.5, Si 1.0, Mn 0.55

Cast (annealed)

33

52

12

130

Axle bearings, track wheels, automotive crankshafts

Ductile or nodular iron

C 3.4, P 0.1, Mn 0.4, Ni 1.0, Mg 0.06

Cast

53

70

18

170

Gears, cams, crankshafts

Ductile or nodular iron (ASTM A339)

—

Cast (quench tempered)

108

135

5

310

—

Ni-hard type 2

C 2.7, Si 0.6, Mn 0.5, Ni 4.5, Cr 2.0

Sand-cast

—

55

–

550

Strength

Ni-resist type 2

C 3.0, Si 2.0, Mn 1.0, Ni 20.0, Cr 2.5

Cast

—

27

2

140

Resistance to heat and corrosion