Small components can make a big difference, especially when one component combines multiple functions. We take a closer look how the humble push nut can have a huge impact, if we add an additional PTFE compound tape as a bearing surface. Creating a unique component by enabling reduction in components, while removing axial tolerances and providing low friction.
At its simplest, a push nut is a washer with teeth, its alternate name is a lock washer. A push nut saves time and cost by simply sliding the product onto the shaft which allows for the teeth/tabs to bite onto the shaft with no need for threads. Once located, the teeth/tabs bite into the shaft locking the washer into place, producing a secure fixing.
Most push nuts are made from spring steel. Aluminium, bronze, stainless steel and plastic are also options, depending on the application. For steel different coatings are used to provide corrosion protection.
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.
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 using them make them a popular fixing component.
Push nuts are an ideal product for designers facing issues of fastening on to a thin walled hollow tube in rotary pivot applications. As a tube can only be fastened on the outer walls by flaring the ends of the tube, the push nut eliminates the need for this, saving both time and money.
On a downside, push nuts are known for creating friction and wear, and are also critical in handling vibrations. This is where Saint-Gobain can help. At Saint-Gobain we have changed the design and added a solid PTFE layer, allowing these to be used in many different applications which significantly reduce the friction, wear and vibration.
An example of this is a push nut that has been designed for fixing the cross tube assembly found on the height adjustment for a car seat.
At Saint-Gobain we manufacture our push nuts from spring steel with a laminated thick layer of PFTE, providing a component that’s both very low friction and strong. Our SPRINGLIDE™ solution has proved so effective that it is now known in the market as the go to solution when designing applications with push nuts.
SPRINGLIDE™ push nuts reduce assembly time and cut costs. The solid PTFE layer 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 the spring steel provides the typical locking function. It acts as both nut and bearing, and removes the need for any additional mechanical forming.
One application, that the Saint-Gobain’s SPRINGLIDE™ push nuts have been used for, is to fix the cross tube to the side member of car seats. The traditional way is time-consuming, and accuracy is difficult as this would mean the use of plain bearings and addition forming steps to fix all together. To overcome this, engineers will swage the tube with the addition of grease, however this is a costly process: our innovative new push nuts make assembly so much simpler.
As well as easier assembly, our push nuts 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 flexible adjustability is key. The PTFE element in our push nuts supports with the reduction of N.V.H.
For this example, the main function of SPRINGLIDE™ is a combined fastener / bearing, a push nut can also be used for many other functions such as rotational torque, for example, in an armrest.
SPRINGLIDE™ utilizes the same world renown NORGLIDE® PTFE technology. The PTFE layer creates a low friction sliding surface but the spring steel gives SPRINGLIDE™ a remarkable flexibility providing a unique combination of features like tolerance compensation, pre-tension or high-strength. There are many advantages of using a combination of PTFE and spring steel as opposed to the traditional spring steel or NORGLIDE® only.
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.