Bolt, High strength bolts, Screw
Head shape There are many types of head shapes. Including circular, oblate, circular with protruding parts, oblate with protruding parts, flat bottomed circular, circular with protruding parts, larger countersunk heads with larger bottom planes, smaller semi countersunk heads with smaller bottom planes, cylindrical, slightly protruding spherical shapes on cylindrical shapes, horn shaped, hexagonal, hexagonal with flange heads, and hexagonal with protruding parts heads, etc. Twisting method The screwing method of a screw refers to the method of twisting its head when tightening it. The basic screwing methods include external screwing and internal screwing. Generally speaking, the allowable torque for external tightening is greater than any form of internal tightening (such as internal grooves). The types of external wrenches include hexagonal, hexagonal flange face, hexagonal flange, hexagonal flower shape, etc; The types of internal wrenching include slot, cross groove H type, cross groove Z type, cross groove F type, square groove, composite groove, internal spline, internal hexagonal flower, internal triangle, internal hexagonal, internal 12 angle, clutch groove, six blade groove, high torque cross groove, etc. Thread type There are various types of threads, including self tapping threads (also known as wide thread), machine threads (also known as regular threads), dry wall nail threads, fiberboard nail threads, and other special threads. In addition, according to the shape and quantity of the helix, threads can also be divided into single lead (single head), double lead (double head), multi lead (multi head), and high and low tooth double head threads. Terminal form The end form mainly includes two types: cone end and flat end. However, according to usage requirements, the threaded part at the end can cut grooves, notches, or parts similar to the shape of a drill bit, making it capable of cutting. In some standards, even with tapered or flat ends, there are different forms, such as rounded ends.
