<p>A rotary tool (10) is in contact with a metal material and rotates and is provided with: a tool shaft (12) the tip of which is made to come into contact with the metal material; a tool case (14) that is attached such that relative motion is possible in a direction in which the tool shaft (12) protrudes to the outside and a direction in which the same goes inside thereof; and a coil compression spring (15) that generates force in the direction in which the tool shaft (12) protrudes to the outside of the tool case (14) according to the relative position of the tools shaft (12) to the tool case (14).</p>
