While injuries from powered hand tools are caused by a number of factors, this study looks specifically at the impact of the tools design features on perceived tool usability and safety. The tools used in this study are circular saws, power drills and power nailers. Sixty-nine males and thirty-two females completed an anonymous web-based questionnaire that provided orthogonal view photographs of the various tools. Subjects or raters provided: 1) description of the respondents or raters, 2) description of the responses from the raters, and 3) analysis of the interrelationships among respondent ratings of tool safety and usability, physical metrics of the tool, and rater demographic information. The results of the study found that safety and usability were dependent materially upon rater history of use and experience, but not upon training in safety and usability, or quality of design features of the tools (e.g., grip diameters, trigger design, guards, etc.). Thus, positive and negative transfer of prior experience with use of powered hand tools is far more important than any expectancy that may be driven by prior safety and usability training, or from the visual cues that are provided by the engineering design of the tool.