Pinch welds are an important part of the auto industry, used in countless projects. But what exactly is a pinch weld and why is it so vital? This guide will explain exactly what pinch welds are and how they work, as well as their importance in auto repair projects.
What is a Pinch Weld?
A pinch weld also known as a spot weld is a method for joining two pieces of sheet metal in a lap joint. It’s commonly used in auto body fabrication and repair, where two pieces of sheet metal—most often those that form the car’s body panels.
Using a combination of heat, pressure, and time. The result is an ultra-strong bond, stronger than if the pieces were riveted or fastened with bolts.
High-strength steels in the automobile manufacturing industries enable spot welding to provide the strongest bond, compared to plug welding with a mig welder.
How Does Spot Welding Work [Three Factors Critical For Sheet Metal Spot Welding]
The following segment is best practices for the setting of industrial spot welding. I think knowing the fundamentals of the below process will help you in knowing what a good spot weld looks like.
Material Thickness and Current
The spot welding process is a type of resistance-based joining technique. An industrial spot welder would be set by knowing the thickness and the material type of sheet metal to be pinch welded. This will determine the amount of current being applied. Each metal has a different thermal conductivity and electrical resistance which changes the amount of current and the actual time the current is passed through the material.
The thickness of the material will also determine the size of the copper alloy electrodes. These are the points that come in contact with the sheet metal having the pinch weld.
Pressure Applied To The Lap Weld Joint
The next welding parameter to be set for resistance spot welding is the amount of pressure being exerted on the base metal before an electric current is passed through the weld joint. It is critical in getting high-quality welds to avoid any gaps between the two metal surfaces.
The electrical resistance passed through the metal sheets creates extreme heat creating the weld pool. Because no filler material is added to the weld joint the joint strength of the spot weld relies on the two base metals fusing together.
The pinch welding process also doesn’t use any shielding gas to prevent any oxidization. With the correct pressure applied by the electrode tips, it excludes the atmosphere from the weld joint.
Welding Time And Cool Down Period
The final parameter in spot welding operations is the time the jaws of the spot welder are pressed against the metal being welded. Dependant of the thickness or property will set the time the electrical current is passed through the work. Usually, only 1 to 2 seconds of welding time because the heat energy from the
electrical resistance generated is massive. Once the desired weld spot size is reached, the electrical current is stopped.
To increase the strength of the spot weld the clamping force of the jaws remains until the weld pool has cooled down from its molten state. Because of the excellent thermal conductivity of the copper electrode tips this happens in the space of seconds too.
Pinch welds offer a secure and efficient way to join two pieces of sheet metal together. This article has provided an overview of the process, as well as the advantages and disadvantages of using this method in the auto industry. With this knowledge, you can decide whether pinch welds are a suitable option for your needs. If you are at the spot weld removal stage a specialized spot weld cutter could be the next read for you. Thanks for checking out this post and I hope you found it helpful.
Frequently Asked Questions
What Are Pinch Welds On A Car
A pinch weld, also known as a spot weld, is a type of welding method used to join two metals together. The process involves clamping the materials together and then applying pressure with an electrode to create a strong bond. This type of welding is commonly used in the automotive industry, especially for sheet metal components such as car body panels.