The use of hand tools can lead to accidents, overexertion injuries and discomfort. So, there is certainly room for better-designed hand tools, especially hand tools that contribute to better performance. In the literature the benefits of a participative product design approach are clearly shown. However, the effect of this approach is hardly ever measured at the hand tool performance level. The goal of this project was to study the effect of a participative product design process on indicators of health, performance and comfort. Two sets of screwdrivers were tested. One set was developed by a participative product design approach and the control by a traditional approach. The study indicates positive effects of the participative approach. Some indicators for health and safety (discomfort in the hand and blisters) were significantly better for the test set compared with the control set. The effect on productivity is clearly shown (16% higher productivity) and the positive effects on comfort are also shown. It is discussed that it is plausible that in the long run some of the effects found in this study would still be seen under real working conditions, but long-term effects on health and safety still need to be studied.