SPOT WELDING: -

• This is one of the type of resistance welding and this is the most used type over all the resistance welding. By this welding process mostly overlapping joints are produced.
•  In the spot welding the coalescence is to be created by flowing the current between the two specimens. The resistance in the specimen will generate the heat and that heat will be used by the system to create the joint.
•  The classification of spot welding is done on the factors like, material to weld, thickness of material, requirement of power resources, requirement of welding equipment etc., on the basis of the thickness of the material and type of material, the power requirement will be decided.
• Electrodes are used to pass the current through the part. The specimen is clamped between the electrodes to pass the current. Generally the copper electrodes are used. In the surfaces of workpieces the cleanliness is required.
• So the process is quite simple, the electrical resistance on the mating surface of the parts ill resist the current flow and the heat generation takes place. The heat will cause the joining of material because the molten metal will be fused into each other and joining process will be completed.
• The whole process is completed in a fraction of time. The solidification of molten metal will be done under pressure by the electrodes and the electrodes will have the property to remove the heat quickly from the surfaces of material. It is very time saving process which increases the production rate.
• Dissimilar materials can be welded by the spot welding process.