In applications where space is limited, specifying one weld can produce a stronger bond than two spots, which may be limited in size and integrity because of contraints in positioning, accessibility and shunting effects (current loss). Typically, diameters of spot welds range from about 1/8 in. (3 mm) to l/2 in. (13 mm) depending on the thicknesses of the workpieces and the material. When the size of spot welds is designated, the designer should specify only one size throughout an assembly in the interest of manufacturing economy and total part cost.
One alternative to plug welding is “MIG spot welding”. It is similar to plug welding, although a hole is not drilled in the front sheet of metal. Instead the power of the MIG is relied upon to fully melt the top sheet and penetrate into the back sheet. This technique would require less preparation work than plug welding, but the two sheets need to be in tight contact and high amps used to complete the weld or else the weld could be very weak. Plug welding is a much more suitable technique for all but the most experienced welders.
Where is Spot Welding Used? Spot welding has applications in a number of industries, including automotive, aerospace, rail, white goods, metal furniture, electronics, medical building and construction. Given the ease with which spot welding can be automated when combined with robots and manipulation systems, it is the most common joining process in high volume manufacturing lines and has in particular been the main joining process in the construction of steel cars for over 100 years. Read more details on Tecna Spot Welder Arms.
In the same category you also find generators, always operating on direct current, intended for car bodywork including repairing dented panels. The machine consists of a holder which lets you position your welding gear precisely in front of the deformed zone, and uses mechanical or hydraulic force to restore it to its original shape. All you have to do is crack out your hammer to fine-tune the finish. The “gougeonneuse”, as it’s known in France, can be used to mend tow rings and other specific parts. The huge advantage of being able to return a panel or component to its original shape without needing to disassemble the car body makes this machine a must-have tool for bodywork!