Cast Iron

Cast iron tends to be brittle, except for malleable cast irons. With its low melting point, good fluidity, castability, excellent machinability and wear resistance, cast irons have become an engineering material with a wide range of applications, including pipes, machine and car parts.

Iron (Fe) accounts for more than 95 %wt of the alloy material, while the main alloying elements are carbon (2.1 to 4 %wt) and silicon (1 to 3 %wt).
Material properties:

Density kg/m3 7000 to 7400
Modulus of elasticity E GPa 83 to 170
Modulus of elasticity G GPa 32 to 69
Poisson’s ratio v 0.2 to 0.3

Note: These properties should be used for indication only as material properties vary from sample to sample.

Cast iron has many uses: flywheels, cylinder liners, pistons, bedplates.


Cast Iron BS1452 Grade 220 – A continuous cast iron bar, it has a fine grain structure combined with the fine graphite flake size and dense homogeneous structure.

Cast Iron BS1452 Grade 250 – Good combination of wear resistance and strength, reasonable machinability and excellent surface finishes.

Cast Iron BS1452 Grade 260 – A fine grain structure, combined with the fine graphite flake size and dense homogeneous structure. Good wearing characteristics and when components require a combination of strength and wear resistance superior to those of other softer cast iron grades.

Uses: Pistons, moulds, dies, bearings, cams, bushes and gears.


All types of cast iron, from gray to ductile, reduce noise because of the inherent damping properties of the metal.

Gears that are subject to high impact forces may not be suitable for ductile iron. Converting to ductile iron is not recommended in cases where added strength is required because of fatigue failures.


About Nigel 225 Articles
Have been making models since I was around 7 years old and using a lathe from the age of 11, a self taught engineer with a passion for making model engines.

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