1. The external edge of the hexagon socket screw is round, with a concave hexagonal center. This structure can bear greater loads, thanks to its six force-bearing surfaces, which are more resistant to twisting compared to the single-edged and cruciform screws that have only two surfaces.

Note: The material of internal hexagon bolts is generally made of stainless steel, carbon steel, or alloy steel, and there is no significant difference in material from other types of screws. The higher the performance grade, the greater the strength. When selecting screws, it is essential to choose the appropriate performance grade strictly according to the usage requirements, as different grades have different prices.

2. Can be fully immersed. The entire screw cap is submerged within the workpiece, maintaining the flatness and aesthetic appeal of the workpiece surface.

3. Easy Installation. Compared to external hex screws, internal hex sockets are suitable for more assembly scenarios, especially in cramped spaces. Therefore, they are convenient for assembly and maintenance, as well as for adjustment.

4. Not easily removable. The tools we commonly use include adjustable wrenches, screwdrivers, and socket wrenches, but removing the internal hex bolt requires a specialized wrench. Therefore, it's not easy for most people to disassemble, which is also a benefit.