Fusion welding is the joining of metals by fusion of component parts either with or without the use of filler metal, and typically without the use of pressure. 

TIG or Tungsten Inert Gas fusion welding depends on an inert gas, such as argon, to provide a protective atmosphere around the weld area. This inert gas shielding prevents oxidation and weld contamination by atmospheric elements.

Electric resistance spot, stitch, seam and tack welding uses the heat created by resistance to an electric current to form a weld. Two or more relatively thin layers of metal can be welded together by passing current between the two electrodes which hold the pieces in contact with each other under pressure. 

Spot welding uses pointed or domed electrodes to create a single point weld or “nugget” as current is passed through the materials

Stitch (overlapping spot) welding uses the spot-welding type electrodes to make a continuous seam. 

Seam welding is electric resistance welding using roller type electrodes to create a continuous weld seam. 

Tack welds are merely holding−type spot welds used for either temporary. 

ETI INC. welding technicians are certified to American Welding Society (AWS) D17.1 criterion.

TIG Machine – Miller Syncrowave 350LX

Electric Resistance Machines- Miller SSW-2040ATT and Sunstone Engineering CD600DP