Small components can make a big difference, especially in the automotive industry. We take a closer look at the humble push nut, and how adding PTFE can have a huge impact on both manufacture and end user experience.
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. They can also have a zinc plated or enamelled coating and can be finished using passivation for 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, wear and vibration. This is where Saint-Gobain can help. At Saint-Gobain we have changed the design and added a PTFE surface, allowing these to be used in many different applications which 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 push nuts.
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.
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 a secondary flanged bush. 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 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 control, a push nut can also be used for many other applications such as rotational torque, for example, armrests.
The SPRINGLIDE™ push nut utilizes the same world renown NORGLIDE® PTFE technology. The PTFE layer creates a low friction sliding surface as well as still providing the typical locking function. There are many advantages of using a combination of PTFE and spring steel as opposed to the traditional spring steel.
• Reduction of rattle and vibration in the cabin, thus making a smoother driving experience
• Zero maintenance: PTFE won’t need greasing during the component’s assembly or lifetime of the assembly
• Misalignment prevention: from the sliding element
• Torque control: the low wear sliding surface delivers consistent torque
• Elimination of any linear play or tolerances
• Cuts down on manufacturing time and costs: fewer parts are required, the lubrication stage is removed, and there is no need to expand the end of the cross-tube to hold it in place
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.