Abstract The average Canadian woman is smaller and lighter than her male counterpart. She is less able to handle heavy weights when tested in the laboratory, although such test results may not apply in the complex conditions of real industrial surroundings. Mechanic is the fourth most common occupation of Canadian men, and is considered a classic non-traditional job for women. We examined in detail a job in a machine shop employing 1200 men and three women. One woman and ten men were assigned to rebuilding diesel engines. The woman was typical of those entering non-traditional jobs in that she was smaller, lighter and less senior than the average worker, and her grip strength, average for a woman, was less than half that of her average co-worker. She and her teammate, a man 17 cm taller with three times her grip strength, were observed for 3 days. Tasks involving exertion of physical force took up less than 4% of the workday. The woman accomplished exactly the same tasks with a similar time allocation. There were few differences in work practices. However, the difference in height, weight and availability of appropriate tools and equipment forced the woman to exert her strength in uncomfortable positions more frequently than the man, which may account for the fact that she reported more pain and difficulty than her fellow workers. Making the height of the work surface adjustable and providing appropriate tools would benefit both larger and smaller workers.