Also called resistance spot welding, spot welding is most often used to weld multiple sheets of metal together. An electric current generates heat and pressure in the weld area, joining the metal pieces together with a strong bond.
Discover the range of materials and considerations involved in spot welding, its advantages, the industries that rely on it, and Cyber-Fab’s advanced spot welding services.
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Spot Welding: Materials Used
Different electrodes make spot welding possible on a wide range of materials, including:
- Steel
- Stainless steel (austenitic and ferritic)
- Galvanized steel
- Low carbon steel
- Aluminum
- Nickel alloys
- Copper
- Titanium
Steel is one of the easier materials to spot weld, due to its combination of low thermal conductivity and high electrical resistance. Low carbon steel is particularly suitable for spot welding.
High carbon steel (with a carbon equivalence over 0.4 wt%) is not as suitable for spot welding because the welds form hard, brittle microstructures susceptible to cracking and fracturing. Zinc-coated galvanized steel also presents unique challenges because it requires a higher welding current and creates surface consistency issues when using copper electrodes. Therefore, the electrode should be changed frequently or dressed, which involves continually removing contaminants from the tip to expose clean copper.
Despite having electrical resistance and thermal conductivity similar to that of copper, aluminum can be spot welded because it has a lower melting point. Aluminum’s low electrical resistance requires up to two or three times more current compared to spot welding steel of the same thickness. Because even just a few welds can quickly degrade the copper electrode, only specialized applications use aluminum spot welding. New technologies are being developed to create more stable high-quality results for spot welding aluminum.
Spot welding is also possible on copper alloys. This requires electrodes made of unique alloys, such as tungsten and molybdenum, which have higher electrical resistance and melting points than copper (over 1080 °C).
Spot Welding: Industries
Many industries rely on spot welding. The automotive industry is one example, as spot welding can be easily integrated into automated robot and manipulation systems. In fact, spot welding has been the most common joining method for producing high-volume steel cars for more than 100 years.
Other industries that require spot welding to maintain efficiency and quality include:
- Aerospace
- Construction
- Electronics
- Furniture
- Medical
- Rail
Spot Welding: Advantages
Spot welding can weld any conductive metal by providing fast, high-energy delivery of electricity to a concentrated spot. The skill and learning threshold for spot welding is lower than that of other forms of welding, which helps save time and labor.
On thin metals, spot welding is the higher-quality welding option, achieving proper weld strength without burning through the material. The electrodes also dissipate heat away from the welding site while maintaining high energy efficiency. This provides greater control over the final weld quality.
Versatility is another advantage. There is a considerable variety of available electrodes that make welding possible on many types of metals. Its repeatability and efficiency make spot welding easy to scale. It is a time-tested resistance welding process with proven reliability and a wealth of technical literature available.
Spot Welding: Capacities and Tolerances
Cyber-Fab’s spot welders are fully certified to MIL-W-6858D standards. We’re also equipped with specialized diaphragm and piston head machines capable of achieving Class A welds on .090” to .090” 6061-T6 aluminum. Subcomponents and assemblies can be spot welded with very tight (+/-.005″) tolerances.
Spot welding is a cost-effective alternative to the more expensive arc welding and polishing processes, especially for closing corners on components. Because spot welding causes far less heat distortion, it preserves the integrity and look of the original materials.
Spot Welding Services From Cyber-Fab
Due to its range of materials and applications, spot welding is the most versatile form of resistance welding. With its ease of use and high degree of control, spot welding is also extremely efficient and cost-effective, making it perfect for welding applications at scale.
For more than 30 years, Cyber-Fab has been providing unparalleled spot welding services for the aerospace, military, electronics, robotics, and other industries. For the most advanced spot welding services with the tightest tolerance levels and quality control, contact us or request a quote today.