Introduction to Spot Welding in CNC or bronze Kerwin)

  • Time:
  • Click:8
  • source:NEWRGY CNC Machining


CNC machining has revolutionized the manufacturing industry with its precision, efficiency, and versatility. One of the essential techniques used within this realm is spot welding. In this article, we will delve into the details of spot welding, describing how it fits into the CNC machining process and highlighting its significance as a critical fabrication method. So, let's unravel the art of spot welding in CNC machining.

What is Spot Welding?

Spot welding is a type of resistance welding that joins two metal surfaces together by creating a strong bond through the application of heat and pressure at specific points, known as weld spots. It is widely used in various industries, including automotive, aerospace, electronics, and more. The primary objective of spot welding is to achieve rapid fusion between metal sheets, resulting in a robust joint that can withstand heavy loads and vibrations.

The Role of Spot Welding in CNC Machining:

In CNC machining, spot welding serves as an integral part of the overall process flow. Typically, after the initial shaping of metal components using computer numerical controlled (CNC) machines, which include milling, turning, or drilling processes, spot welding comes into play for assembling these parts together. By securely joining different pieces, spot welding ensures structural strength and stability, enabling complex designs to take shape.

Spot Welding Process:

1. Preparation - First and foremost, the metal components that need to be joined together undergo thorough cleaning to remove any contaminants or oxidation present on their surfaces. This step is crucial as the cleanliness of the material directly impacts the quality of the weld.

2. Clamping - Once cleaned, the metal pieces are carefully aligned and clamped tightly using specialized fixtures or jigs. Proper alignment guarantees accurate positioning during the welding process.

3. Electrodes Selection - Spot welding utilizes a pair of electrodes, one acting as the positive side and the other serving as the negative side. The electrode selection depends on the material being welded, its thickness, and other factors.

4. Welding Parameters - To ensure optimal spot welds, various parameters such as current, voltage, time duration, and pressure need to be set accurately according to the characteristics of the materials involved. CNC machining systems allow for precise control over these variables, ensuring consistent welding results.

5. Spot Weld Formation - Once all parameters are set, an electric current is passed through the positive electrode into one piece of metal while the negative electrode applies pressure simultaneously. This causes localized heat generation due to electrical resistance at the contact points, melting the metals and forming a strong bond.

Advantages of Spot Welding in CNC Machining:

1. Speed and Efficiency - Spot welding offers high-speed joining capabilities, making it suitable for mass production scenarios where quick assembly is essential.

2. Cost-Effective - Compared to alternative techniques like soldering or riveting, spot welding proves to be cost-effective due to minimal material consumption and reduced labor requirements.

3. Strong and Durable Joints - Spot welds provide exceptional strength and durability when compared to other joining methods. They resist deformation, external forces, extreme temperatures, and environmental conditions.

4. Aesthetic Appeal - Since spot welding does not require additional materials like adhesives or fasteners, the joint appearance remains clean and unobtrusive, often desirable from an aesthetic standpoint.


Spot welding plays a crucial role in CNC machining by securely joining metal components together to create complex assemblies. Its ability to provide robust and durable joints, coupled with cost-effectiveness and efficiency, makes it a preferred choice in numerous industries. As CNC machines continue to advance, so does the significance of spot welding within the manufacturing landscape. Understanding its principles and applications empowers manufacturers to harness its benefits appropriately and pave the way for innovative design and production possibilities. CNC Milling CNC Machining