Electric spanner

The utility model relates to an electric spanner comprising an impact block which is pivoted on an impact bracket. A protruded part is arranged on one end of the impact block, and the end of the impact block is adjacent to the impact bracket. Two corresponding centrifugal weight bodies, a left one and a right one, are pivoted on the impact bracket. One spring is arranged one end of each of centrifugal weight bodies in a hook way, and the end of each of centrifugal weight bodies is far away from the pivoted end of each of centrifugal weight bodies and is provided with a wrap around edge surface. Besides, the wrap around edge surface can wrap the protruded part of the impact block, and an impact bar which can drive a tool assembly to rotate is sheathed on the front end of the coupled bar arranged on the impact bracket. Due to the components of the utility model, when the rotary speed of a motor achieves a set value, the two centrifugal weight bodies adopting the pivoted ends as axle centers are thrown out. Thus, wrap actions to the impact block are stopped, and the impact block is enabled to swing in a deflection way and poke the impact bar to act.