Machining tool for box-end wrench and method of machining box-end wrench by using the same

A machining tool for a box-end wrench, comprising:

• a fixed pillar;
• a cutting tool unit including a finishing cutting tool provided with a first teeth portion around an outer surface thereof, a rough cutting tool provided with a second teeth portion around an outer surface thereof, and a punching tool provided with a third teeth portion around an outer surface thereof;
• and
• a support member passing through the punching tool, the rough cutting tool, and the finishing cutting tool in sequence and detachably mounted to the fixed pillar, the support member enabling the finishing cutting tool, the rough cutting tool, and the punching tool to be sequentially connected with the fixed pillar in a direction away from the fixed pillar;
• wherein the finishing cutting tool has a diameter defined between two opposite tooth valleys of the first teeth portion;
• the rough cutting tool has a diameter defined between two opposite tooth valleys of the second teeth portion;
• and the punching tool has a diameter defined between two opposite tooth valleys of the third teeth portion;
• an outer diameter of the fixed pillar is slightly smaller than the diameter of the finishing cutting tool, and the diameter of the finishing cutting tool is slightly greater than the diameter of the rough cutting tool, and the diameter of the rough cutting tool is slightly greater than the diameter of the punching tool.