The saying 'the sharper the hair clipper, the more you use it' is not mystical, as it mainly hides two scientific secrets: mechanical grinding and surface cleaning.
Firstly, the core automatic grinding technology. There is a tiny spring device between the moving and fixed blades of some hair clippers. When the motor is running at high speed, the spring will continue to apply pressure, making the two blade heads tightly adhere. In long-term relative high-speed friction, the surface of the blade will form a micro grinding effect similar to a "sharpening stone", which automatically corrects the cutting edge and maintains a sharp gap.
Next is the "false sharpness" caused by dirt removal. After long-term use, hair clippers are prone to residual debris, dandruff, and oil in the gaps between the teeth, which can increase shear resistance and cause hair to be pulled. By regularly cleaning or using particles such as salt for idle grinding, the oxide film and attachments on the blade surface can be effectively removed, restoring smooth cutting force and giving the hair clipper a "sharp" feel again.
However, it should be noted that this self grinding effect has its physical limits. As time goes by, the cutting head will still face normal metal fatigue and wear. When there is a noticeable pulling sensation or a decrease in trimming efficiency, the cutting head still needs to be replaced in a timely manner.
