How to fundamentally distinguish between loose threads and self-locking threads?

The formulation and inspection of the difference between the self-locking thread and the self-locking thread and the self-locking thread The threaded fasteners we currently use have the properties of anti-looseness and self-locking. Some of them are originally loose threads, but they are self-locking threads. 1. The basic judgment of the self-locking threading pair is based on the self-locking thread and the loosening thread. At least one difference is: The self-locking thread refers to a thread pair consisting of an external thread and an internal thread. Itself (but not outside) ) It is self-locking.

The Substantial Differences between Locking Threads and Self-locking Threads and the Formulation and Inspection of Self-locking Performance Standards

The threaded fasteners we use today have anti-loose and self-locking properties. Some of the original anti-loosening threads are said to be self-locking threads. So, how do you distinguish between them?

1. The basic judgment of the self-locking threading pair is based on the self-locking thread and the loosening thread. At least one difference is: The self-locking thread refers to a thread pair consisting of an external thread and an internal thread. Itself (but not outside) ) It has self-locking performance. Its auxiliary evaluation index should be: the internal and external threads of the main dental profile should be the same, it should also be the same as the traditional profile, not one is a triangular thread, the other is a rectangular thread, trapezoidal thread, sawtooth thread, wedge thread combination. Among them, the United States product "shall be secure" is a triangular thread and wedge thread composed of self-locking thread. Another indicator is that the self-locking threading joints should be re-installable and reusable; the anti-loosening performance resulting from the addition of auxiliary means or measures from one threading pair, such as the addition of spring washers, and the addition of nylon inserts. , screw sleeves and other fillings, damage thread profile, and even welding, are all measures to prevent loosening, species of threading, can only be said to be anti-loose threading pair; there is a situation that is double threading to achieve self-locking With the anti-loosening performance, this thread pair cannot be integrated into the category of self-locking thread. Such as double nut anti-loose, slotted nut, high lock nut and so on.

2. Judging whether the self-locking performance of the threading pair is good or bad, the two national standards determine whether the threading self-locking or anti-loosening performance is good or bad. China has two standards, one is the national standard and the other is the national standard. The testing equipment for testing in accordance with national standards is very complicated. It is said that only one department of the country has one, but no other standard parts factories in the country have deployed the testing equipment. The national standard only specifies the method of detection and is a method standard. As long as a standard shaking table device is equipped and relevant fixtures are manufactured according to the standards, the self-locking performance of the relevant thread pair can be achieved. Tested. It is based on the actual use of the situation, to simulate the situation of the anti-lateral vibration of the thread design. As far as the detection conditions are concerned, testing according to national standards is much simpler and easier than testing according to national standards, and testing costs are also lower. According to the comparison of domestic experts, the self-locking thread couple can pass the national standard test if it can pass the national standard test. On the other hand, passing national standards will be more difficult than passing national standards. Our aerospace and aerospace products, whose self-locking properties of the thread pair, are tested according to this standard.

3. Recommendations for the development of self-locking performance standards We recommend that our manufacturers, when developing self-developed self-locking threaded fastener product standards, should use our national standards** GJB715.3 as a basic standard. This standard is also an equivalent standard using the United States standards. It is international and highly reliable.