How Do Nuts That Claim to Never Loosen Work?

In both daily life and industrial production, we often face a common issue: long-term vibration causing originally sturdy screws to gradually become loose, thereby planting potential safety hazards. To crack this problem), a multitude of nuts claiming to be "never-loosening" have emerged in the market, among which the Japanese Hard Lock nut has garnered significant attention.

The imported nuts used in our country's high-speed trains are from the Japanese Hard Lock (Hard Lock) Industrial Co., Ltd., a company with only 49 employees. These nuts are not only favored in our country but have also been ordered by technologically advanced countries like the UK, Australia, and the USA. Hard Lock has taken the small nut to the pinnacle of perfection.

The principle of the Hard Lock nut is actually quite simple. It uses a combination of two nuts with "concave" and "convex" shapes. The convex nut is slightly off-center during machining, acting as a wedge, while the concave nut maintains circular machining, creating the effect of a hammer driving a wedge. This innovative design fundamentally solves the loosening issue.

Apart from the Hard Lock nut, are there other methods to ensure nuts never come loose? The answer is yes. The Swedish company NORD-LOCK, which has been dedicated to solving bolt loosening issues since 1982, has introduced the NORD-LOCK X series of washers, an innovative product in this field.

Common washers available on the market do not perform well in vibration tests, whereas the NORD-LOCK X series anti-loosening washers demonstrate exceptional performance. This product consists of two washers and uses a new sandwich composite material technology, combining geometric principles with a unique wedging function to effectively prevent bolt loosening.

The cam angle of the NORD-LOCK X series washers is greater than the thread pitch angle of the bolt, creating a wedging effect that, when combined with elastic effects, effectively prevents the nut from rotating, sinking, and loosening. Once the bolt is tightened, the large toothed surfaces move and lift, locking the bolt in place with the principle of angle-over-angle, ensuring it does not come loose.

The lifting distance between the two NORD-LOCK washers is greater than the lifting distance caused by thread slippage of the bolt or nut, thereby preventing any loosening tendency. Here are the performance test results for the NORD-LOCK X series:
Through the above introduction, we believe you now have a deeper understanding of the performance and principle of the NORD-LOCK washers. Innovation in science and technology has brought new development opportunities to our fastener industry.