Nucor falls as market focuses on 3Q guidance

Other U.S. steel makers also declined, though not as much as the Charlotte, N.C.-based company.

Nucor, which reported surprisingly strong second-quarter earnings and sales, said it expects third-quarter earnings per share of $1.80 to $1.85. Analysts expect, on average, earnings per share of $1.95 for the period, according to a Thomson Financial poll.

Shares tumbled $7.45, or 11.1 percent, to $59.81 Thursday.

Goldman Sachs analyst Aldo Mazzaferro said part of the reason that Nucor's third-quarter guidance was lower than he expected may be due to "higher scrap costs and lower spreads on downstream markets, where it is more difficult to pass on higher costs for steel."

United States Steel Corp. fell $8.82, or 5.7 percent, to $145.19, and AK Steel Holding Corp.--which reports second-quarter earnings next week--fell $5.14, or 9.6 percent, to $48.24.

Schnitzer Steel Industries Inc. fell $8.65, or 9.2 percent, to $85.65.