1.
Cast iron is iron which contains a small amount of carbon. It is hard and cannot be bent so it has to be made into objects by casting.
Made from ~, it is finished in graphite enamel.
...the cast-iron chair legs.
N-UNCOUNT
2.
A cast-iron guarantee or alibi is one that is absolutely certain to be effective and will not fail you.
They would have to offer cast-iron guarantees to invest in long-term projects.
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