After the saw chain is used for a period of time, the blade head will become blunt. At this time, you need to use a professional file to repair the file.

Different saw chains have different file sizes. The file size is matched according to the design of the cutter head, generally 5/32", 11/64", 3/16", 7/32".
When repairing the file head, pay attention to the angle of the file. This angle determines whether your blade will continue to be sharp after the file is repaired. Some cutter heads will have an indication line for the file. Make sure to keep it parallel. Note that 1/5 of the file must leak out of the top surface of the head.

Finally, the file should be repaired from the inside to the outside of the cutter head.
Maintenance of limit teeth. As the cutter head is repaired and filed, the top surface of the cutter head gradually becomes lower. At this time, the depth of the cutter head into the wood becomes shallow, which will cause the cutting to slow down. It is necessary to file the limit teeth of the cutter head. A flat file is used here, and the use of a limiting tooth positioning tool can better complete this action.