SAE J158 M5503: Liquid‑Quenched, Tempered Malleable Iron for Superior Machinability

Malleable iron is a cast iron in which the graphite is present as temper carbon nodules, instead of flakes as gray iron or spherulites as in ductile iron. M5503 is used where better machinability and/or improved response to induction hardening than M5003 are necessary for parts requiring moderate strength.

Properties

General

Property	Temperature	Value	Comment
Density	23.0 °C	7.2 - 7.34 g/cm³	Typical for Malleable Cast Iron

Mechanical

Property	Temperature	Value	Comment
Elastic modulus	23.0 °C	179 GPa
Elongation	23.0 °C	3 %
Hardness, Brinell	23.0 °C	187 - 241 [-]
Poisson's ratio	23.0 °C	0.27 [-]	Typical for Malleable Cast Iron
Shear modulus	23.0 °C	64 GPa	Typical for Malleable Cast Iron
Tensile strength	23.0 °C	517 MPa
Yield strength	23.0 °C	379 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion	23.0 °C	1E-5 - 1.4E-5 1/K	Typical for Malleable Cast Iron
Melting point		1120 °C	Typical for Cast Iron
Specific heat capacity	23.0 °C	460 - 527 J/(kg·K)	Typical for Malleable Cast Iron
Thermal conductivity	23.0 °C	51 W/(m·K)	Typical for Malleable Cast Iron

Chemical properties

Property	Value	Comment
Carbon	2.2 - 2.9 %
Iron	93.6 - 96.71 %	balance
Manganese	0.15 - 1.25 %
Phosphorus	0.02 - 0.1 %
Silicon	0.9 - 1.9 %
Sulfur	0.02 - 0.2 %

Technological properties

Property
Application areas	Parts requiring moderate strength.
Processing history	as agreed

SAE J158 Grade M5003: Air‑Quenched & Tempered Malleable Cast Iron SAE J158 Grade M7002: Liquid Quenched & Tempered Malleable Cast Iron

Metal