Abstract
This study aims to investigate the effect of handle angles of pliers on performances of task completion time and the number of errors, and subjective ratings of preference. For doing this, an experiment was conducted, where 14 subjects of 11 college-age male and three female students participated. In the experiment, plier handles angled at $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$ were used as independent variable, and the task completion time and the number of errors, and subjective ratings of preference as dependent variables. The subjects were instructed to do two tasks of bending an iron plate by $90^{\circ}$ and cutting wires. The results revealed that while the performances of task completion time and the number of errors were not statistically different depending upon the handle angles of pliers, the subjective ratings of preference were significantly different. Based on the results, it is recommended that the pliers with handles bent by $20^{\circ}$ be used in real situations.