Special nut to prevent screw loosening
Solutions against screw loosening under vibrations conditions - a special nut to prevent screw loosening
Eccentric Lock Washer™ SWAS-EW
The Japanese manufacturer NBK1560 has developed a unique solution protected by a patent, of a set consisting of a special disk and a nut designed to prevent the loosening of screws under vibration conditions.
Vibration conditions that develops in any machine in which a linear or rotary mechanical drive is carried out, cause screws to loosen which may lead to malfunctions ranging from a defect in the quality of the work to a malfunction that leads to the complete destruction of the machine.
In order to prevent or reduce these vibrations, there are a selection of solutions offered by the various manufacturers represented in the Medital group, see the following page: ACE
In cases where the vibrations cannot be avoided - we recommend using the NBK solution which is proven to pass strict NASA vibration tests according to an aviation standard.
NBK's solution for prevent screws from loosening during vibrations works in such a way that the disk is eccentric and there is a special nut on top of it, and when the screw is closed with a normal nut above the NBK set, together with the special nut placed on the disk, a 3-point engagement is created into the screw, where radial and axial force develops which locks the disk and the nut to the screw and prevents the screw from being released as shown in the picture:
Link to the product page:
Today the set exists in 6 sizes between 4 mm and 12 mm and in the future there will be additional sizes as well as inch sizes. Special sizes can be requested if a large quantity is required.
More anti-vibrations solutions are available here :