1. Loss of anti-loosening function
If the flange face (especially the serrated side) faces outwards, it cannot engage with the surface of the connected parts, losing its mechanical anti-loosening function.
Under vibration or dynamic load conditions, the nut is prone to loosening and falling off, causing equipment failure or safety accidents.
2. Uneven stress and localized crushing
When the flange face faces outwards, its function of increasing contact area and dispersing pressure fails, causing the load to concentrate at the edge of the nut body.
The surface of the connected parts (especially soft materials such as aluminum alloys and plastics) is prone to indentation, deformation, or crushing, affecting structural integrity.
3. Degraded sealing performance
In sealing scenarios such as pipelines and pressure vessels, the flange face needs to work in conjunction with the sealing gasket. Incorrect orientation will disrupt the sealing surface contact, leading to media leakage.
Leakage may cause serious consequences such as fire, explosion, poisoning, or environmental pollution, especially in high-temperature, high-pressure, or corrosive media environments.
4. Insufficient Thread Engagement and Risk of Disengagement
Incorrect installation with the threaded end facing inwards may result in the nut not being fully screwed in, leading to insufficient thread engagement length.
Under high preload or dynamic loads, this can easily cause stripping and disengagement, resulting in complete connection failure.
5. Difficult Maintenance and Increased Costs
Exposed flange surfaces may be damaged by impacts or corrosion, increasing the difficulty of later maintenance.
In the event of loosening or leakage, machine shutdown, disassembly, and reinstallation are required, increasing labor and material costs and potentially causing production interruptions.
