What is a Nut?
A nut is a common type of mechanical fastener, notable for its internally threaded hole. Nuts are almost exclusively used alongside bolts for joining components together, securing assemblies through thread friction, bolt stretching, and compression. For installation, the bolt is first passed through the preformed hole of two components before the nut is screwed onto the opposite side. With the placement of the bolt and nut, the bolt serves to prevent radial movement while the nut prevents axial movement. Depending on the application and its needs, there are numerous nut types that one may use, each presenting varying designs and installation characteristics that can make them more beneficial for certain assemblies.
The hex nut
is considered to be the most common variation, featuring a hexagonal outer shape that accommodates easy installation with the use of a simple tool. Hexagonal shapes are quite beneficial as compared to designs with a different number of sides as they provide an easier installation grip even in tight spots and avoid rounding off. While retaining the hex nut shape, such components may come in numerous sizes and materials to accommodate a variety of applications.
When there is concern for fasteners
loosening due to vibration or other forces, a special nut known as a locknut may be used. Locknuts
can come in two types, those of which use friction for preventing loosening and those that use positive locking devices. With friction locknuts, an increased amount of torque may be needed to achieve a tight fit. Nylon locknuts are a common example, featuring a collar that has a smaller diameter than the outer thread. As the collar deforms during installation, it will cause friction and resist loosening. Positive locknuts, on the other hand, can freely tighten and loosen until a positive action is performed on them. Depending on the fastener, the positive action may come in the form of inserting a pin, clip, or safety wire.
The flange nut
is a mechanical fastener with a wide flange on one side, acting as an integrated washer. The flange helps provide a larger surface for bearing increased loads with more distribution. This mitigates the chance that the nut may become damaged and prevents loosening due to uneven surfaces. The flange nut is most commonly constructed with a hexagonal shape, providing the same installation benefits as the standard hex nut type.
Cage nuts are a more unique type, featuring a nut that is wrapped within a spring steel cage. By squeezing together two wings that extend from the sides of the cage, the fastener may be inserted into a square hole. This allows for quick and simple installation without the need for tooling. A cage nut may be used alongside a number of bolt and nut sizes, and they are regularly implemented for the means of mounting equipment on 19-inch racks.
While nuts are commonly paired with bolts, they can also be used alongside other fastener types as well. Nuts are compatible with matching sized screw and stud components, utilizing their external threading for attachment. As a stud
is devoid of any head, two nuts may be tightened on each side of the fastener after it has been passed through the holes of components in order to secure an assembly. With screws
, on the other hand, the nut can simply be twisted onto the tail-end of the component for a tight fit.
Posted on May 28, 2021