Small components can make a big difference, especially when one component combines multiple functions. We take a closer look at the humble push nut and how, by adding an additional PTFE compound tape as a bearing surface, it can have a huge impact on the push nut's capabilities; creating a unique component that can reduce the number of components in a system while removing axial tolerances and providing low friction.
At its simplest, a push nut is a push-on fastener that securely fastens cylindrical components, with locking geometry, they can be designed with or without teeth. A push nut saves time and cost by simply sliding the product onto the shaft which allows for the locking geometry to bite onto the shaft with no need for threads.
The push nut needs to be of a higher strength material than the tube or shaft’s material: if it’s lower strength than the shaft, the washer’s teeth won’t bite in. Most are made from carbon steel, as well as stainless steel and spring steels. The application will determine the material type as different materials will alter the performance. They can also have a zinc plated or enameled coating and can be finished using passivation for corrosion protection.
Push nuts are found in a wide range of applications and are most commonly used by the automotive industry but they’re also found in places as diverse as medical applications and children’s toys. The speed and ease of assembly makes them a popular fixing component.
They are an ideal product for designers facing issues of fastening on to a thin walled hollow tube in rotary pivot applications. Tubes can only be fastened on the outer walls and this is traditionally done by swaging the ends of the tube. Where loads allow the push nut eliminates the need for this, saving both time and money. On a downside, they are known for creating friction, wear and vibration.
This is where our SPRINGLIDE™ solution can help. We have studied the design and along with customizing the geometry, we have added a PTFE surface, allowing ours to be used in many different applications and reduce the friction, wear and vibration.
SPRINGLIDE™ push nuts reduce assembly time and cut costs. The PTFE surface allows for a better quality feel with the additional advantages of a reduction in noise and friction.
The PTFE layer creates a low friction sliding surface as well as providing the typical locking function. It acts as both nut and bearing, and removes the need for a secondary flange.
We manufacture our push nuts from spring steel with a laminated thick layer of PTFE, providing a component that’s both very low friction and strong. Our solution is proving to be very effective and is now being used more widely and gaining in popularity.
One application, they have been used for, is to fix the cross tube to the side member of car seats. The traditional way is time-consuming, accuracy is difficult and, depending on application, it could require the use of a secondary flanged bush, swaging the cross tube and the addition of grease. This is a costly process. To reduce complexity and the number of assembly steps we have developed our innovative SPRINGLIDE™ push nut.
As well as easier assembly, they can make a huge difference to the end user’s experience. As electric vehicles are becoming the norm in the automotive industry, driver comfort and vibration reduction is key. The PTFE element in our push nuts supports with the reduction of N.V.H.
Although this is one example of using SPRINGLIDE™, for linear fastening, a push nut can also be used for many other applications such as rotational torque, for example, in armrests.
Find out more about SPRINGLIDE™ by contacting us at Saint-Gobain. We’ll discuss your application with you, engineer to engineer, and find the right component.
Contact us using the Contact Us Form or email us at: makingabigdifference@saint-gobain.com