Abstract: A tool includes a socket and an attachment that includes a shaft portion. The shaft portion transmits torque to the socket. The socket includes a distal end face, a proximal end face, an accommodation hole that opens in the distal end face, and a connection hole that opens in the proximal end face and is connected to the accommodation hole. The shaft portion includes an outer peripheral surface provided with a first transmission surface for transmitting torque to the inner peripheral surface of the connection hole. The accommodation hole includes an inner peripheral surface provided with a second transmission surface for transmitting torque to threaded fastener. The accommodation hole forms an accommodation space capable of accommodating threaded fasteners in a row. The shaft portion includes, at a distal end, a contact portion, which contacts one of the threaded fasteners accommodated in the accommodation space.