An employee was installing a rail on a machine. The roller pack was locked up, causing the chuck to not move. While manually removing the chuck, the rails were damaged. As a result, both the roller pack and the rail needed to be replaced. A fixed magnet from above the rail pulled the rail up and rolled it, pinching the employee's thumb between the rail and the magnet when he tried to install the new rail back to the position. The right thumb tip was amputated.