The left and right cutting teeth on the saw chain are cutting tools. After a period of use, the cutting edge becomes blunt. In order to cut smoothly and keep the cutting edge sharp, it is necessary to file.

Note for file repair:
1. Choose a round file suitable for repairing the saw chain. The cutting teeth, size, and arc of various types of saw chains are different. Each type of chain requires a certain round file standard. There are detailed instructions in the manual, and you must pay attention to it.

2. Pay attention to the direction and angle of the file. The file should be repaired in the direction of the cutting edge. When pulling back, it should be light. Do not use force back and forth as much as possible. Generally, the angle of the cutting edge of the saw chain is about 30 degrees, and the front is high and the back is low. The included angle is about 10 degrees. These angles vary according to the hardness of the material being sawed and the usage habits of the saw. At the same time, attention should be paid to the symmetry of the left and right cutting teeth. If the deviation is too large, the saw will run off and the saw will be oblique.

3. Pay attention to the height of the limit tooth. A part of the front of each cutting tooth protrudes, this is the limit tooth, which is 0.6---0.8 mm lower than the upper edge of the cutting edge, and the cutting amount per tooth is so thick. When filing the cutting edge, pay attention to its height. If the cutting edge is repaired more, the relative cutting edge of the limit tooth will become higher, and the cutting amount will be smaller each time, which will affect the cutting speed. If the cutting edge is lower than the limit tooth, it will produce no wood , Unable to cut, the limit tooth repair file is too low, and each tooth is too thick each time, it is likely to cause the "knife" and the saw will not move.