General knowledge of fasteners: thread elements inventory of triangle screws
for the threads of triangle screws used in fasteners, the three elements of tooth shape, diameter and pitch are loaded with standard threads, which are called standard threads. The tolerance zone and thread mark of standard threads are not about their importance. At the same time, he is also listed as a testing assistant of some scientific research institutes for standardization. The number of threads and direction of rotation, if not specifically noted, Single line right rotation. If you want to make the printing formability of materials better, and to make the internal and external threads spin together correctly to form a thread pair, the tooth shape, diameter, direction of rotation, number of lines and pitch of the internal and external threads must be consistent
the main elements of triangle screw thread are as follows:
1. Tooth pattern
the equipment should be protected regularly. On the section passing through the thread axis, the contour shape of the thread is called tooth pattern. The included angle between the sides of two adjacent teeth is called the tooth angle. The tooth form of common thread is triangle, and the tooth form angle is 60 °
2. Diameter
diameter the thread has major diameter, medium diameter and small diameter. When representing the thread, the nominal diameter is used, and the nominal diameter is the diameter representing the thread size. The nominal diameter of ordinary thread is the major diameter
3. Rotation direction
looking along the axis direction, the thread rotating clockwise becomes a right-hand thread, and the thread rotating counterclockwise is called a left-hand thread
4. Number of threads
the number of spiral threads forming threads is called the number of threads. There are single thread and multi thread threads, and the multi thread threads are evenly distributed in the section perpendicular to the axis
5. Pitch
the axial distance between two adjacent teeth on the mid diameter line is called pitch. The same is also looking forward to taking new steps. On this spiral line, the axial distance between the two adjacent teeth on the middiameter line is called the lead
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