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SOLUTIONS: Cast Iron

How to identify cast iron Cast iron will, as the name implies, always be in the form of casting. Castings have one thing in common; they will have no welded joints, and most often they will have a visible casting line where the two halves of the mold they were cast in met. One can easily identify a copper alloy or an aluminum alloy casting by their color. However, to distinguish between cast steel and cast iron by appearance alone is not easy. To help us establish which metal a casting is made from we have a couple of easy tests.

The perhaps simplest method to distinguish cast iron from cast steel is to use a hammer and chisel on a place of the casting where a little chiseling will do no harm. Cast steel when chiseled will from a continuous chip, while the cast iron forms no chip but comes away in small fragments: A spark test will also give ready identification between the types of ferrous metals.

2.07

Shaving

Mild steel

The leaf is smaller and gives rise to a number of sparks. Some streaks are shorter.

Cast iron

Unalloyed steel (Cast steel).

Faint red streaks terminating in complex bushy sparks yellow in colour. GREY CAST MALLEABLE IRON CAST IRON

Chips Volume of Stream Relative Length Colour at Wheel Colour at end

Cast iron.

Small 0.6 m Red Straw

Moderate 0.75 m Straw

Description of

Many small Longer shaft spark stream repeating than grey (compare with sprigs.

iron, small known samples).

repeating sprigs.

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