Views: 0 Author: Site Editor Publish Time: 2025-08-08 Origin: Site
In the field of metalworking, spot welding machines are commonly used welding equipment. They generate heat through electric current to bring the contact points of the workpieces to their melting point, fusing them together to achieve the weld. However, due to the differing physical properties of various materials, each has distinct welding requirements. Therefore, selecting the appropriate spot welder is crucial to ensuring weld quality and improving production efficiency.
Black metals—such as carbon steel, alloy steel, and stainless steel—are the most widely used metallic materials in industrial production. These metals have relatively high electrical resistance, making medium-frequency (MF) spot welders the ideal choice. MF welders employ direct-current (DC) discharge welding, effectively addressing the high-resistance characteristics of black metals. They can apply single-pulse, multi-pulse signals, cycles, time, voltage, current, and programmable control to perform single-spot, dual-spot continuous, automatic, or manual welding on the workpiece. Their advantages are notable:
1. Good overall cost-effectiveness and high value.
2. A wide welding-condition window accommodating black-metal workpieces of various thicknesses and shapes.
3. Compact and lightweight welding loops, facilitating installation and mobility.
4. Capability to weld dissimilar black metals—e.g., carbon steel to stainless steel.
Non-ferrous metals—such as copper, aluminum, and silver—have high electrical and thermal conductivity, requiring specialized equipment. Capacitor-discharge (energy-storage) spot welders are ideal for these metals. They use stored energy in capacitors to deliver a rapid, concentrated current with strong penetration and minimal heat-affected zone (HAZ), perfectly matching the demands of highly conductive materials. They are suitable for welding sheets, rods, and wires of silver contacts, copper, aluminum, stainless steel, and other non-ferrous metals. Compared with other welders, they offer more accurate and stable current output, higher efficiency, smaller HAZ, and lower energy consumption than MF welders.
However, their initial cost is higher. Once the machine is configured, discharge time is fixed by stored energy and the welding transformer and cannot be adjusted. Furthermore, the discharge capacitors gradually degrade over time and require periodic replacement.
For special metals such as phosphor bronze, manganese bronze, or copper braided wire, conventional welders are inadequate. AC brazing welders—classified as a subset of AC spot welders—are recommended. They use AC discharge welding, leveraging the welding transformer’s duty cycle together with graphite (or tungsten) electrodes to create a high-resistance, high-heat zone. Single-pulse, multi-pulse, cycle, time, voltage, current, and programmable controls allow single-spot, dual-spot continuous, automatic, or manual welding. AC brazing welders share many advantages: good cost-effectiveness, a broad welding-condition range, compact and lightweight loops, and the ability to weld dissimilar metals. However, they are also affected by grid-voltage fluctuations, causing unstable current and inconsistent welds, and they demand high-quality electrode materials with relatively short electrode life.
For butt welding of wire or rod materials, butt welders are required. They are divided into two-stage and three-stage models. For example, the machine for welding hard metal wires used in metal-halide lamps is called a “hard-wire lead machine,” whereas the one for soft wires used in energy-saving lamps, fluorescent lamps, and ordinary incandescent lamps is called a “soft-wire lead machine.”
For hermetic sealing applications, cap-sealing machines are the standard choice. They automatically perform inspection, indexing, sealing, vacuum pumping, nitrogen filling, welding, and reset. If incorrect manual loading occurs, the machine withholds welding to protect the welding dies. By modifying the welding dies, cap-sealing machines can also be adapted to other hermetic-sealing tasks.
If you are still unsure which spot welder best suits your needs, consider PDKJ welders. We cordially invite you to visit us at EMO Hannover 2025, September 22–26, at the Hannover Exhibition Grounds, Germany. You will find us in Hall 13, Stand F21. There, you can witness the outstanding performance of PDKJ welders firsthand, discuss your requirements with our professional
If you have welding machine requirements, please contact Ms. Zhao
E-Mail: pdkj@gd-pw.com
Phone: +86-13631765713
