Spot Welder Guide

What Is a Spot Welder?

A spot welder, also known as a resistance spot welder, is a type of welding machine that utilizes pressure and heat to combine two or more pieces of sheet metal. The pressure and heat brought by the electrical current usually come from the copper electrode. When the spot welder is in use, it welds on the workpieces with small spots instead of welding a large area. This working principle makes spot welder a perfect choice for manufacturers who aims for efficient and cost-effective operation.

Types of Spot Welders

Depending on the main difference in the operation methods, spot welders can be categorizes into two types, which are the portable spot welders and battery spot welders. The former relies more on operator’s manipulation, while the latter can focus more on relatively thinner workpieces.

● Portable spot welders

As the name suggests, the portable spot welder is of the compact type that is able to be held by operator’s hand. Despite the convenient nature, this type requires the experienced operator to operate. With this type, position and alignment are the important factors that determine the success or failure of the operation. When using this device, make sure the sheet metals are in the right position, and the electrodes are properly aligned. 

● Battery spot welders

The battery spot welders are especially used for welding several batteries together for other usages. Compared to the conventional spot welders, this type doesn’t require the operator to squeeze the welder. Due to the primary purpose of the battery spot welder, it is able to weld on smaller and thinner area, which would be fragile if using the other type.

How Does a Spot Welder Work?

During operation of spot welding, the necessary elements are the electrodes and the workpieces. The electrodes are usually made of copper with the high thermal conductivity and low electrical resistance it has. The thermal conductivity of the electrodes allows the sheet metal to be molten, which facilitates faster welding process. Moreover, the low electrical resistance of copper degrades the workpieces, which is also helpful for welding the workpieces together.

When it comes to the working process of welding, the filler material is the medium that welds the workpieces. While for spot welding, it doesn’t require any filler material. Instead, the electrodes play the role of welding medium. As spot welding is applied, two or more sheet metals are placed in the middle, and the electrodes clamp on the workpieces from the two sides. After the spot welding process, a spot of welding area is created. This means the upper and lower parts of electrodes, and the welding area should be properly aligned. 

Once all the elements are in place, the electrical current is turned on, and the electricity would be conveyed to the electrodes as well as the welding area. The conventional form of spot welder is often the squeeze type, which means the electrodes make the squeezing force to the workpieces during the process. When the heat generated through the electricity and the pressure produced with the squeezing force, the welding area would start melting. After the molten area is solidified, the process is finished and the targeted sheet metals are fused together.

Advantages of Using Spot Welders

● Easy to get on

With the design of electrodes that are aligned with each other, they naturally create a clamping force for the targeted workpieces. This eliminates the need of extra clamping equipment, and allows the operator to manage the welder under control, which is easy for the operator to get on.

● Cost-effective

As mentioned above, what the spot welder need for the welding medium is electrical current. This means that there is no waste of filler materials produced when other welding techniques are applied. While this operation method can also make the corresponding effect like that of other welding techniques, which makes spot welding a cost-effective choice for the manufacturers.

● High productivity

Another advantage of using spot welders is the high productivity they contribute to. For one thing, the cost saved on the welding medium allows for more flexibility of the input. For another, the heat generated by the electrical current is controllable, which prevents the problem of overheating. Moreover, the welding area created by spots would not burn the unwanted parts of workpieces, which ensures the optimal quality of the products. For the manufacturers who pursue high productivity, spot welders are the perfect choice for you to apply.

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