"The last time oil prices were at the levels seen in today's trading session, U.S. Steel's tubular business saw a contraction in overall rig counts and began generating negative operating margins ," Johnson said, according to Barron's . "While we are modeling U.S. Steel's Tubular operating margins at just under 10% in 2015, if we assume these margins go to zero, after-tax this represents about 80 cents per share in EPS downside.