How to provide flawless, holding power when connecting metals without welding
Updated: May 18, 2021
By Josh Price
Follow him on LinkedIn
Do you have a brushed stainless or polished aluminum that looks fantastic until it gets burn marks from a laser? Consider two options that can create the results you need. This is part of a broader focus on cosmetic welding that is often not talked enough about in the industry.
OPTION 1 - Withstanding 1600 pounds of pressure
To withstand 1600 pounds of weight and hold two metal pieces together, the Pemserter® presses a nut into a metal piece without having to weld it.
When you put the holes into the metal using the Pemserter®, the area around the hole hardens while using a laser, and won’t take the PEM® Fasteners (pem nuts).
Example – When there is a higher risk of a fire
In this example, we’ve inserted pem nuts in this customer’s commercial electrical cabinets because there is an electrical panel inside. You can see that the pem studs are in the white powder coated panel opposite of the orange door in order to add pem studs.
This customer didn’t want burn marks because if someone were to inspect the electrical cabinet, they could think there was a risk of a fire if they saw them.
Here you can see a second example of a commercial electrical cabinet and the pem nuts that were used.
Pem nut benefits include:
keeping the beauty of a brushed stainless or polished aluminum without having the burn outs that welding or laser cutting can cause
holding more weight, roughly 400-16000 pounds
being more substantial, weighty and stout
reducing time of cleaning it after welding – creating more efficiency, and therefore, lower costs for customers
Pem nuts are often used when:
material is too thin to tap
it is needed earlier in the process before welding & assembly
you don’t have to be as precise with holes. It is more forgiving for a “floating nut”
OPTION 2 - The poor man’s version of a Pemserter® has great applications
Often called the poor man’s version of a Pemserter®, the Shearex RIVNUT® gun puts RIVNUT® (rivet nut) fasteners into the metal.
With our pneumatic rivet nut guns, it ratchets and squeezes the metal like a sandwich in the material. The nut slides out on a gun and squeezes and mushrooms between the two sides of the metal, sandwiching itself, with two flanges in the outer rims.
Example - Floating nut requiring less accuracy & more attractive cosmetic finish
In this example, these bond-in rails (an electrical connection between the metallic parts of traction rails) holds temperature-controlled cargo on airplanes. The plates hold the components together.
A lot of people would do a welded nut. However, in this situation, we chose a floating pem nut, a specialty floating nut, because it doesn’t have to be 100% accurate when bolting other pieces into it.
Rivet nut are often used when:
more flexibility is required, taking the gun to the part instead of the part to the machine
tight corners or pre-made projects require finishing
you need to transport it to the customer to replace damaged pem nuts
there are bigger holes than pem nuts
Benefits of a rivet nut include:
faster than a Pemserter® machine because it squeezes it like a gun and can set it up faster as a handheld tool
holding quite a bit more weight than pem nuts can
good for aluminum since there are no burn marks (along with beauty of stainless steel)
does not take as much pressure to put it in