| 摘要 |
A threaded fastener, such as a screw or a bolt, has a central longitudinal axis in a z-axis direction. The fastener has a head and a threaded shaft. The head has an overhanging periphery in an x-y plane and at least two slots, evenly-spaced apart, that extend completely through the overhanging periphery. Each slot has a sloped surface that undercuts the overhanging periphery in the same tangential direction. The screw is turned by using a bit that has a central longitudinal axis in a z-axis direction. The bit has a shank fixed to an end portion and at least two legs, evenly-spaced apart, extend from the end portion in a z-axis direction. Each leg has a sloped surface that extends in the same tangential direction.
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