Resistance welding

Electric resistance welding (ERW) is a process by which metal can be joined by applying pressure and heating the joining ends by passing strong electric current. Different resistance welding methods are :

Spot welding
Seam welding
Butt welding
Projection welding

Advantages

Similar or dissimilar metals can be joined
Highly automated
No need of flux material
Economical

Limitations

Less efficient for high conductive material
High electric power is required
The thickness of part can be joined is limited
Costlier machines and skilled labour required