Push-on fasteners are also known as push-in fasteners or push-on retainers. They are hardware components that provide the capability for the components to be assembled quickly and securely to a smooth shaft. The push-on fittings are designed with radial teeth or radial fingers in a direction perpendicular to the shaft. This angle permits the fastener to slide smoothly along the shaft only in one direction and avoids moving in the opposite direction, which provides sliding resistance to the assembly.
The barbs on fish hooks and the porcupine quills have a similar principle to this attachment mechanism. During the assembly with such a mechanism, the fastener can quickly slide on the shaft, allowing immediate holding power.
Types of Push-On Fasteners
- Push-On Nuts: Other names for Push-on nuts are Push-On retainers and external fixing washers. These are the most common types of push-on fasteners. It is always crucial to ensure that the shaft material is softer than the nut.
- Push-On Hat Retainers: As the name indicates, this type of pus-on fastener consists of a hat at the end of the rod or shaft, and it offers protective and aesthetic benefits. They are known by the alternative names of cap nut, washer cap push nut, and hammer cap push nut.
- Speed Nut: The name indicates that this type of fastener functions faster than others. The speed nut slides quickly onto the shaft, and then it is locked in place with a radial motion applied to the shelf-threading feature.
- Push-On Bolt Retainer: Push-On bolt retainer slips onto the screws to hold them in one place in the panel or other assemblies while a traditional nut is installed.
Applications of Push-On Fasteners
Push fasteners are highly cost-efficient and can save you a lot of assembly time in an adequately suited application. Along with providing a finished attachment function, a push-on pin can temporarily hold the on to the assembly until a more excellent strength mechanism is attached like a locknut. When there is a physical transit between assembly stations, the complex and multi-staged assemblies will benefit most. Push-on fasteners can be used in various applications that include medical, automotive, and consumer products, like toy or furniture assemblies that mostly contain axles and shafts.
Specifications
It is crucial to consider the design of the rod or the shaft. When the shaft diameter is tight, that ensures that the push nut will apply the requisite amount of force. The rod material needs to be hard enough but not exceed a value where it will not be able to allow the locking teeth to dig in. the shaft and cutoffs need to be chamfered or rounded, that will allow an easy and quick mounting of the push retainer.
Materials
The standard material used in manufacturing push-on retainers is spring steel. Other materials that best suit operating situations include aluminum, stainless steel, plastic, and bronze. The coatings and finishes determine the durability of the retainers. The typical finishes may include passivation, zinc plating, and enameling.
Benefits of Push-On Fasteners
- Push-on fasteners are designed to hold the components in place on rods, shafts, or axles.
- Retainers get rid of secondary operations that could be costly, like threading, notching, or drilling.
- Push-on fastener allows for easy and fast assembly. They can be easily pushed down on a shaft or a stud.
- They have excellent material and standard finishes.
