Punching tool

A punching tool, comprising:

• a punch driver transmitting an impact force to a punch body, the punch driver including a screw portion on an outer peripheral surface of an upper portion;
• a punch head including a screw portion meshed with the screw portion of the punch driver on an inside surface, the punch head including a main scale provided in a vertical direction on an outside surface;
• a punch head rotation prevention mechanism to selectively fix the punch head with respect to the punch driver and release the punch head to rotate relative to the punch driver;
• and
• a punch head collar mounted to the punch driver, the punch head collar including a sub scale showing a change of a height of the punch head in cooperation with the main scale;
• wherein the punch head rotation prevention mechanism comprises:
• a plurality of grooves extending in a vertical direction on an outer peripheral surface of the punch driver;
• a stopper pin preventing the punch head from rotating by passing through the punch head so as to fit to the groove;
• and
• a collar freely movable in a vertical direction, wherein the collar is located outside the punch head;
• wherein
• the collar is urged upward so as to insert the stopper pin into the groove so that the punch head cannot be rotated with respect to the punch drive;
• and
• wherein the collar allows the punch head to rotate when the collar is moved downward.