Resistance spot welding (RSW) is a process in which contacting metal surfaces are joined by the heat obtained from resistance to electric current. Work-pieces are held together under pressure exerted by electrodes. Typically the sheets are in the 0.5 to 3 mm thickness range.
The attractive feature of spot welding is that a lot of energy can be delivered to the spot in a very short time (approx 10–100 milliseconds). This permits the welding to occur without excessive heating of the remainder of the sheet.
Essentially, inserts are special nut or stud fasteners that are designed to be pressed into prepared holes in sheet metal parts. Inserts provide captive male or female threads in materials too thin to tap, when higher strength fastening is required, or when repeated access after assembly is anticipated. Economically, they are routinely less expensive than the conventional nut and bolt alternative. A great number of different inserts are available in various thread sizes, lengths, classes of fit, materials and finishes to fit virtually all design requirements.
A fast, reliable and accurate method of welding a metal fastener to another metal object. The resultant weld joint is stronger than the stud or parent material. Improved product design is achieved since reverse marking is eliminated and the area around the stud is flat and clean.
GRAINING AND POLISHING
This process is often used to enhance the look of an item, prevent contamination in components, remove oxidation, create a reflective surface or blend in welded joints.