3 July 2017

Advantages and disadvantages of projection welding

Projection welding is also called as resistance welding produces coalescence of welding material, the heat generated from electric resistance to current through the workpiece hold together with pressure applied to electrodes. Let us have a deep insight into the pros and cons of projection welding in this article. 

Advantages of projection welding :

  • It is possible to weld more than one spot at a given time. The number of welds depends on the number of projections that can come under the tip of the electrode. Up to about 6 welds per cycle can be made which substantially reduces the cost of manufacture.
  • The welds may be placed closer than possible in spot welding.
  • Because of the large-sized electrodes used, their life is much longer than that of the spot welding electrode. The larger contact area makes for very limited deformation of the welding tip.
  • They can help in holding the workpieces together in proper alignment during the welding process.
  • Proper heat balance can be easily obtained in projection welding by making the projections in thicker plates while welding sheets of different thickness. 
  • For welding dissimilar metals, the projections are to be made on the material having higher electrical conductivity to provide proper heat balance.
  • The uniformity and appearance of the weld are much better compared to spot welding.

Disadvantages of projection welding :

  • Prior operation of embossing is required before welding.
  • Electrodes are often to be specially made for a particular operation. This can only be justified when production rates and volumes are large.