Cage nut

As a cage nut (or cage nut ) is called a usually square nut, which is contained in an equally square cage made ​​of sheet metal. By means of the cage, the nut can be fixed to a sheet, so that even in thin sheets in which no thread to be cut, a female thread can be provided. Cage nuts are considered a special design of square nuts, as used in switchboards, standardized in DIN 557.

The cage is provided with lugs which can snap in the sheet metal in a generally also square hole. The hole is slightly smaller than the cage so that there is a circulation between plate and nut for receiving the threaded axial force present. The direction of force is to be chosen so that the nut is pressed against the sheet metal. The form-fit between the nut and plate on the snapping lugs suitable for receiving the torque when tightening and loosening of the screw.

Cage nuts are used primarily in the attachment of devices in 19 -inch racks, for example, components of servers, network distributors or laboratory equipment. The front panel of the device is fixed with screws to the cage nuts on the rack frame. The usual size is M6, M5 rare.

An older use of cage nuts were in the automotive industry, as there are also many more mounting points on thin sheets, in which you can not cut a thread. Often, at the end of the back side of the sheets no longer accessible, so that the nut is to be placed first. Due to increased use of welding technology, the application was pushed back in this area.