Tecna spot welder online shopping
Spot welding is often selected for joining sheet metal fabrications, stampings and assemblies because it is fast, reliable and economical. However, numerous design considerations can affect the quality and cost of the weld, among them: size of the spot weld, accessibility, positioning, materials and thicknesses being joined, and the number of spots needed to attain the desired strength. This section will focus primarily on resistance spot welding (RSW) and resistance projection welding (RPW) since these processes are most commonly used due to their speed and flexibility. See Figure 1, for schematics of RSW and RPW.
Position the welding torch with the wire in the center of the hole contacting the back sheet of metal. It is important to arc against this back sheet rather than on the edge of the hole, otherwise the weld might not penetrate into the back sheet. The torch should ideally be pointing directly into the hole rather than at the angle in the photograph. Start welding in this position and don’t move the welder until the hole is almost full of weld. Then move the welder outwards in ever increasing circles until the weld is completed.
Copper and its alloys can also be joined by resistance spot welding, although spot welding copper cannot be easily achieved with conventional copper alloy spot welding electrodes, as heat generation in the electrodes and work piece are very similar. The solution to welding copper is to use an electrode made of an alloy with a high electrical resistance and a melting temperature far in excess of the melting point of copper (much greater than 1080°C). Electrode materials typically used for spot welding copper include molybdenum and tungsten. See more details at Tecna Spot Welder.
Stationary spot welders are mounted on a column with a jack and mobile arms. The frame is heavy and bulky and the machine has a welding capacity of 0.5–10mm. The body of the machine often equipped with a 380V generator and two arms with a mechanical, pneumatic or hydraulic jack to adjust operating height, as well as heat-resistant electrodes made of copper or copper-chromium alloy. No electric arc is produced, and the arms are water-cooled in closed circuit. The arms and electrodes are interchangeable to vary spot size and form across different types of weld.