After filming was completed, Woody Harrelson walked up to director Scott Cooper, hugged him and said "I have never wanted to shed a character so badly in my life".
Christian Bale learned to operate a furnace for the film and didn't use a double for his scenes inside the steel mill.
In 2011, co-writer and director Scott Cooper promised Christian Bale that Cooper wouldn't make this thriller without him. Unfortunately, Bale's schedule didn't permit him to participate in the project, but Bale couldn't get the story out of his mind. Later on, Bale's schedule cleared up, and the shooting of the film commenced in April 2012.
Having Christian Bale attached as the lead proved to be a successful magnet for attracting other big names like Casey Affleck and Zoe Saldaña who all wanted to work with him.