The alloys of iron are steel , manganese steel and stainless steel .
Steel is a mixture of iron and carbon .
Steel is cheap , strong and easily shaped . It is the main metal for construction , including bridges , buildings , ships and vehicles . Over half of the steel used each year in the UK is recycled . Manganese steel is extremely hard and is used for railroad switches and dredging equipment . It is used for cookware , cutlery and industrial chemical plant .