What is "steely iron"

Steely \Steel"y\ (-[y^]), a.

1. Made of steel; consisting of steel. ``The steely point of Clifford's lance.''
   --Shak.

   Around his shop the steely sparkles flew.
   --Gay.

2. Resembling steel; hard; firm; having the color of steel. ``His hair was steely gray.''
   --The Century.

   She would unarm her noble heart of that steely resistance against the sweet blows of love.
   --Sir P. Sidney.

   Steely iron, a compound of iron containing less than one half of one per cent of carbon.

n. A compound of iron containing less than 0.5 percent carbon.