Are Self-Clinching Sheet Metal Fasteners Better Than Weld Fasteners?
Designing sheet metal components with fasteners incorporated into the design is commonplace and offers many advantages. Streamlined assembly, strong connections, and cost savings to name a few.
But how are these fasteners secured in place? Or rather, how should they be? That’s up for debate.
Broadly, these types of fasteners fall into two categories:
Weld fasteners, most commonly weld nuts or weld studs.
Self-clinching fasteners, often referred to by brand name such as PEM Fasteners or Strux Fasteners.
As a custom metal fabrication shop, we at PMMCO manufacture a wide variety of products that require fasteners. We’ve installed just about every type of fastener available, and for most applications, we prefer to use self-clinching sheet metal fasteners, as they are reliable, easy to install, and cost-effective. However, as we strive to provide comprehensive metal fabrication services, we can, of course, install weld fasteners if your sheet metal fabrication project requires them.
What’s the Problem with Weld Fasteners?
Though welding is common in sheet metal fabrication, weld fasteners have become largely unnecessary with high-quality self-clinching fasteners readily available. However, beyond pragmatism, weld fasteners can often cause several issues that may negatively impact the final quality of a part.
Low Corrosion Resistance
To be welded securely, weld fasteners must be made from a weldable material, typically low-carbon steel with no protective finish. In addition, if the base sheet metal is a coated material such as galvanized, the coating is burned off in the area around the weld fastener.
Risk of Damage to Parts
When welding a fastener into place, the fastener’s threads can become distorted due to the high pressure and heat required during the process. This can make it difficult to install mating fasteners in downstream operations.
Additionally, the welding process often creates expulsion, which is tiny droplets of molten material, and these droplets can land and fuse into the threads of the fastener or onto the sheet metal itself.
Why Use Self-Clinching Sheet Metal Fasteners?
Using self-clinching sheet metal fasteners has several advantages, resulting in lower manufacturing costs often and better-quality parts and products.
Ease of Installation
One of the biggest advantages of self-clinching fasteners is how easy they are to install. Unlike weld fasteners, self-clinching fasteners are pressed into place, and the surrounding material cold flows into a recess or undercut on the underside of the fastener’s head. This creates a mechanical bond between the fastener and the sheet metal panel, providing a strong and secure connection between the two parts.
Fast, Simple Installation for Small Projects
For smaller projects, we can install self-clinching sheet metal fasteners quickly and efficiently using a handheld tool to press them into place. Not only is this much faster than welding, but it doesn’t require welding skills or equipment, reducing potential bottlenecks on the shop floor.
Cost-Saving, One-Press Installation for Large Projects
If a sheet metal part requires a large quantity of self-clinching fasteners, we can install them all at once using a press brake or stamping press, which is incredibly efficient. This saves a significant amount of time and can substantially reduce manufacturing labor costs for this stage of production, often by up to 40%.
Better Quality Parts
Beyond time and cost savings, self-clinching sheet metal fasteners simply often result in better quality parts and products due to how they’re installed.
Superior Fit and Finish
As we mentioned, welding can burn off protective coatings such as galvanized, cause thread distortion, or result in spatter and expulsion that can damage a part. With self-clinching fasteners, none of this can occur, as there’s no welding involved.
In addition, self-clinching fasteners come pre-finished, and since the coating isn’t burned off during welding, they don’t have to be refinished to prevent rust and corrosion. The same is true of the sheet metal panel they’re installed into, which can be finished either before or after fastener installation – whichever is most efficient, depending on your project’s requirements.
Compatible with Thin Sheet Metal
Another huge advantage of self-clinching fasteners is how effective they are for projects requiring thin sheet metal. While weld nuts are also an option, the heat of welding again poses an issue, as it can warp the thin sheet metal or weaken the material in the heat-affected zone around the fastener.
However, self-clinching fasteners can be easily inserted into thin sheet metal, create a strong bond, and pose no risk of damaging the part.
Self-Clinching Fasteners: A Cost-Effective Solution for Custom Fabrication Projects
Compared to weld nuts, using self-clinching fasteners in sheet metal manufacturing is typically more cost-effective and results in a higher-quality product with a better fit and finish. While there are some instances where weld nuts are a more cost-effective solution, such as in very high-volume production where installation is automated, self-clinching fasteners provide better results in most custom fabrication projects.
At PMMCO, we provide a comprehensive range of custom metal fabrication solutions and are experts in manufacturing parts and products for numerous industries and applications. Whether your project demands self-clinching sheet metal fasteners or you require the expertise of our precision welding services to install weld fasteners for a specific application, we can provide you with the metal fabrication services you need.
Have a project you’d like to discuss with our team? Request a quote today to get started.