As we all know, the screw head of an Allen screw is round on the outside and concave hexagon in the middle. In fact, such a structure has obvious advantages.
1. It can withstand greater loads. It has six bearing surfaces, which is more bearable than slotted screws and cross screws with only two surfaces.

2. The hexagon socket bolt can be countersunk in use, that is, the whole nut is sunk into the workpiece, which can maintain the flatness and beauty of the workpiece surface.

3. Compared with the outer hexagon screw, the inner hexagon is suitable for more assembly occasions, especially narrow occasions. Therefore, it is very convenient for assembly and maintenance and debugging.

4. The tools we usually use include open-end wrench, screwdriver and solid wrench, etc., and a special wrench must be used to disassemble the hexagon socket bolt. Therefore, it is not easy for ordinary people to disassemble, which is also a benefit.