Thermit Welding


Thermit welding is a welding process that involves the use of a chemical reaction to produce heat to join two metal parts together. It is also known as aluminothermic welding, because the reaction that produces the heat involves aluminum powder and a metal oxide.


Thermit welding was invented in 1895 by a German chemist named Hans Goldschmidt. He was trying to find a way to produce pure metals from their ores, but he discovered that the reaction could also be used to produce heat for welding.


The thermit welding process involves a chemical reaction that produces a large amount of heat, which is used to melt the metal parts to be joined. The process involves the following steps:

  1. Place the metal parts to be joined in a special crucible that is designed for thermit welding.
  2. Add aluminum powder and a metal oxide to the crucible.
  3. Ignite the mixture, which will produce a chemical reaction that generates heat.
  4. The heat produced by the reaction is sufficient to melt the metal parts and fuse them together.
  5. Once the metal has cooled and solidified, the excess material can be removed by grinding or machining.




Thermit welding is commonly used in the railway industry for welding rails together. It is also used in the repair and maintenance of heavy machinery, as well as in the construction of large metal structures such as bridges and buildings.


Thermit welding is a specialized welding process that uses a chemical reaction to produce heat to join metal parts together. While it has its advantages and disadvantages, it is an important welding process that has many practical applications in various industries.