Patent attributes
An impact tool includes: a spindle disposed in a housing; an anvil disposed in front of the spindle and rotatably supported by the housing through a metal bearing, a rear surface of the anvil having a bearing hole in which a front end of the spindle is received; an impact mechanism configured to transmit a rotation of the spindle to the anvil; an outer groove formed on an outer periphery of the anvil and opposed to the metal bearing; and a connecting opening radially extending in the anvil and connecting the bearing hole and the outer groove to provide a communication therebetween. The outer groove is formed to have a depth in the range of 3-10% of an outer diameter of the anvil, and the connecting opening opens at a rear end of the outer groove in an axial direction of the anvil.