The difference between screw full thread and half thread

Overview of full and half thread

In machining, screws are often used as fasteners, in which full thread and half thread are the two types of screws. Full thread is the length of the thread on the whole screw is the same, its main role is to increase the friction force, so that the friction between the screw and the fixed object becomes larger, so as to achieve a stronger fixation. Whole thread screws are widely used in wood and soft plastics. The half thread is only one part of the thread length is equal, and the other part is no thread segment. The main function of the screw half thread is easy to lock the position, only need to rotate to a certain position, the thread clamping phenomenon occurs, without screwing to the bottom. Semi-dental screws are usually used in hard materials such as steel plate, iron plate and other applications. As a result, full thread are more compact than half thread and are subjected to a larger load.

The difference between thread depth and pitch

Thread depth:

The thread depth of the whole thread is deeper than that of the half thread, that is, the whole thread is more stable and firm than the half thread for the same length and width, and can withstand more pressure.

thread spacing:

thread distance is the distance between two adjacent thread on the same spiral. Whole thread are more spaced than half thread, and the distance between the two thread directly affects their tightness and ability to bear loads. Therefore, whole thread are more suitable for large loads than half thread.

Differences in applicable scenarios

Because of the short thread section, the half-thread screw has less resistance and less effort to install, especially suitable for the fastening connection of thicker or harder materials. The smooth rod section can pass through the upper plate, and the thread focuses on the lower plate or nut, so that the connecting parts are pressed tightly together to obtain a firmer and more stable structure.

Full thread screw thread covers the whole body, the bite area is larger, more suitable for wood, plastic and other soft materials and thin plate connection. When connecting multiple members, full-thread screws can provide uniform occlusion in the full length range, more flexible installation position, and more convenient adjustment.