What is "hard steel"

Hard steel \Hard steel\ Steel hardened by the addition of other elements, as manganese, phosphorus, or (usually) carbon.

n. steel with more than 0.3% carbon

Hard Steel is a 1942 British drama film directed by Norman Walker and starring Wilfrid Lawson, Betty Stockfeld and John Stuart. It was based on the novel Steel Saraband by Roger Dataller. The film was one of four made by G.H.W. Productions backed by the Rank Organisation. The film follows the rise of an ambitious steel worker as he is appointed to run his local steel mill. He soon outrages the employees with his ruthless behaviour - and his negligence leads to the accidental death of one of the workers. As the Second World War breaks out he realises what he has become, and seeks a chance of redemption.