1. Decarbonization

The steel is an alloy of iron and carbon, and decarburization is the loss of surface carbon due to high temperature when the file blank is annealed. Since iron is left after the carbon is lost, if the decarburized part is not completely ground when the surface of the file is polished, the cutting ability of the final file will be greatly reduced. (After all, the hardness of iron is much lower than that of steel. Of course, iron filings on the surface cannot be compared with the performance of steel).

2. Teeth

The biggest indicator of the file is the angle of the tooth pattern. A good file is to ensure that the file is sharp and the chip removal is smooth. If it is only sharp, it is easy to clip out the debris under the file, and it is necessary to file when working. It is necessary to clean the surface after a few times, otherwise it will not be able to continue after being filled with debris. If only the chip is smooth and the file is not sharp, then there is no need to say it, as you can imagine.

3. Heat treatment

The file needs to be quenched after cutting teeth. Our company requires that it must reach HRC62 or above, so that the file produced can ensure the sharpness of the cutting. However, because the higher the hardness is required during quenching, the temperature control needs to be extremely rigorous. Once a deviation occurs, it is easy to cause a whole batch of files to crack (the files will be broken into several pieces when they are knocked hard). The quenching hardness of the file will be correspondingly reduced. Once the hardness decreases, the cutting and other factors will naturally reduce the grade.

4. Anti-rust

Generally, the file will rust after shipment, and the cracked file will be shipped.