Why does the Squirrel® fastener effectively solve the loosening problem?

This is because of its unique structure. There is a 30 degree wedge bevel at the bottom of the female thread. When the bolts and nuts are tightened to each other, the tip of the bolt is tightly placed on the wedge-shaped bevel of the Spitz® thread, resulting in a large locking. force. Due to the change in the angle of the tooth, the normal force generated by the contact between the threads is at an angle of 60 degrees to the axis of the bolt, rather than a 30 degree angle like a normal thread. Obviously, the Squirrel® thread normal pressure is much greater than the fastening pressure, so the resulting anti-loose friction force is bound to increase greatly. At the same time, when the male thread crest is engaged with the Spiral® female thread, the tip of the tooth is easily deformed, so that the load is evenly distributed over the entire length of the contacting spiral (see Figure 1), avoiding the standard thread occlusion. At the time, more than 80% of the total load is concentrated on the thread faces of the first and second teeth. Therefore, the Spire® threaded coupling pair not only overcomes the disadvantage that the common standard coupling pair is easy to loosen under vibration conditions, but also prolongs the service life.