Hexagon screws with the head divided into a cylindrical head of hexagon bolts, the most commonly used, and it itself has many kinds, according to the material of iron, that is, carbon steel and stainless steel points. Stainless steel hexagon bolts also have stainless steel SUS304 and SUS202 and so on. semicircle head hexagon bolts, this also has a screw in the pan heads. Countersunk head hexagon bolts, head is flat, inside is hexagon. There is also a kind of national standard is special, called the headless hexagon bolt. We often call the machine screws, pay screws, screw fastening. This is the universal name of Hexagon Bolt without head, but the meaning is the same. Of course, there are also some flower-shaped hexagon head bolts. The use of this relatively few, the market is also basically difficult to see. HEXAGON SCREW Although the standard of the kind is also more, but basically some relatively special, basically the market generally few people will go to use. More than the use of a number of cylindrical head hexagon screws, also called the Cylinder head hexagon screw.