Abstract: On August 25, 2005, Employee #1, a new employee of Machine Services, Inc., was assigned the task of polishing various metal shafts that were approximately 25-inch long by 1-inch in diameter and attached to a lathe chuck, rotating at approximately 425 rpm. Prior to the start of the task, Employee #1 was given verbal instructions by her supervisor, including a demonstration of the task. She was also allowed to demonstrate back to the supervisor that she could perform the task. After receiving the instructions and successfully demonstrating the task, Employee #1 began using a polishing cloth to perform the task. She successfully polished four shafts, but in the process of polishing the fifth shaft, she put her left hand too close to the rotating chuck and her thumb was struck by the chuck, resulting in its amputation.