Maximum Torque for Small Knobs Operated with and without Gloves

An experiment was conducted to determine the maximum torque that men in the standing position can apply to diamond-knurled knobs ⅜, ½ and J in. in diameter if the men brace themselves with their free hand. A total of 120 subjects operated these knobs with and without gloves and with the knobs on both a front panel and a panel facing to the right. Although the results were significantly influenced by many variables and interactions, only differences in knob size had a marked effect on the 5th percentile values normally used as design maxima. It was concluded that the standard maximum torque limits should be 44 in, oz for ⅜ in., 56 in.-oz for ½ in. and 90 in.-oz for ¾ in. diamond-knurled knobs.