Difference Between Welding, Soldering and Brazing

Welding, brazing and soldering are the methods of joining two or more pieces of metal and others materials. They are also used to fill gaps in metal parts. Each types of joining process has its own significance. Metal joining process to be applied for joining two parts depends on many factors. Below see the comparison of welding, brazing and soldering in aspects like strength, temperature requirement, change in properties, cost involvement, heat treatment etc.

Tabular Difference Between Welding ,Soldering and Brazing

S.No	Welding	Soldering	Brazing
1	Welding joints are strongest joints used to bear the load. Strength of the welded portion of joint is usually more than the strength of base metal.	Soldering joints are weakest joints out of three. Not meant to bear the load. Use to make electrical contacts generally.	Brazing are weaker than welding joints but stronger than soldering joints. This can be used to bear the load up to some extent.
2	Temperature required is 3800 degree Centigrade in Welding joints.	Temperature requirement is up to 450 degree Centigrade in Soldering joints.	Temperature may go to 600 degree Centigrade in Brazing joints.
3	Work piece to be joined need to be heated till their melting point.	Heating of the work pieces is not required	Work pieces are heated but below their melting point.
4	Mechanical properties of base metal may change at the joint due to heating and cooling.	No change in mechanical properties after joining.	May change in mechanical properties of joint but it is almost negligible.
5	Heat cost is involved and high skill level is required.	Cost involved and skill requirements are very low.	Cost involved and sill required are in between others two.
6	Heat treatment is generally required to eliminate undesirable effects of welding.	No heat treatment is required.	No heat treatment is required after brazing.
7	No preheating of workpiece is required before welding as it is carried out at high temperature.	Preheating of workpieces before soldering is good for making good quality joint.	Preheating is desirable to make strong joint as brazing is carried out at relatively low temperature.