Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal,

Advantages

  1. The generally cost of welding equipment is commonly low.
  2. Relative simplicity and portability of equipment.
  3. Many portable welding instruments are available.
  4. A large number of metals can be welded.
  5. A good weld is as strong as base metal.
  6. Welding can mechanized for assembly.
    1. It produces a permanent joint.

Disadvantages 

  1. As welding produces inside stresses, the work piece often require annealing or stress-relieving.
  2. Welding gives off dangerous radiations similar to light, fumes and spatters.
  3. Capable welder is necessary for performing a good welding process.
  4. Welding make lasting stresses and distortion in workpieces.
  5. Welding create structural, physical, and chemical changes.
  6. Edging preparation is commonly necessary before welding.
  7. Jigs and fixtures are desirable to hold parts in place.