n this case study, a Korean company trialed many self-lock nuts for their electric scooters to ensure joints could withstand the extra shock and vibrations expected with an increase in speed. The core joints were where the scooter frame and front fork meet, thus the self-lock nut had to be chosen carefully. The connections of moveable elements enforced low torque requirements on the fasteners. The most common loosening prevention tactic is to use higher torque to increase friction on seated and threaded surfaces. Low torquing solutions are quite limited, and most products have prevailing torque, meaning that you apply torque even before the nut is seated onto the fastening surface.

HARDLOCK NUT, in this case, was exactly what the company needed.

• High torquing of nuts prevented loosening but worsened agility of moveable elements.
• There were shocks and vibrations when the scooter travels over bumps and groves on the road. The manufacturer planned to use self-lock nuts to prevent injuries and fatalities caused by loose nuts.
• Spring type self-lock nuts were originally trialed. However, such prevailing torque nuts required special tools. The positioning of the nut was also difficult, due to prevailing torque restraints.
• Self-lock prevailing nuts which increased friction to the threads were also trialed, but loosening prevention testing showed their inability to prevent loosening.

HARDLOCK Nut’s on the front fork

• HARDLOCK NUT allows for locking the threads in any position. This is possible because of the wedging principal that is employed when the top nut is torqued onto the bottom nut.
• HARDLOCK NUT can be reused without any need for replacement parts, allowing easy inspection and maintenance.
• HARDLOCK NUT does not require any special tooling or special tightening techniques to achieve a good lock. Installation and removal are extremely easy.
• Easy installation and removal have been great advantages to the company for cost and time reduction.