Grease contamination issues had been a persistent problem at the United States Steel Corp.’s Granite City Works in St. Louis, Illinois, causing bearings on its hot strip mill roller table to fail prematurely, in turn resulting in table roll damage and failures.
Data collected over a 16-year period showed that 30 percent of all the company’s table roll failures could be attributed to bearing failures. In the past three years, these failures were increasing in number, accounting for more than 50 percent of table roll failures.
U.S. Steel decided that a disciplined, structured approach was needed to find the right solution to the problem. A first step was to pump more grease into the bearing housings, but this only made the problem worse. As a strategic partner of U.S. Steel, SKF was asked to investigate possible improvements in the reliability, focusing on efficiencies that would result in less product waste as well as cost savings.