Welding is the act of joining two or more pieces of metal by melting and joining them with a filler metal.
The welded metal is melted by means of an electrical current that arcs between the welding gun and the workpiece. In the image, the gun is what is being held by the operator, and the arc is clearly visible. The heat produced by the arc melts both the base metal and the filler metal. The area consisting of melted base and filler metal is referred to as the weld bead. When the bead solidifies, the metal has been joined together.
WHY USE WELDING?
Welding can be used for a multitude of different manufacturing applications and is used for the quality and speed in which it can join metal. There are several different types of welding, all with advantages, disadvantages, and specific areas of use. For example TIG or GTAW (gas tungsten arc welding) can be used for applications requiring high quality and control over the weld bead, while stick welding is used for its versatility, portability, and speed. The type of welding that will be used in this instructional document is MIG or GMAW (Gas metal arc welding). MIG is one of the most widely used forms of welding in industry and is considered one of the easier forms of welding to learn. Anyone with access to a welding machine can take advantage of this manufacturing process.