# List of welding processes

This is a list of welding processes, separated into their respective categories. The associated N reference numbers (second column) are specified in ISO 4063 (in the European Union published as EN ISO 4063). Numbers in parentheses are obsolete and were removed from the current (1998) version of ISO 4063. The AWS reference codes of the American Welding Society are commonly used in North America.

## Arc welding

Overview article: arc welding
| Name | N | AWS | Characteristics | Applications |
| Bare Metal Arc Welding | (113) | BMAW | Consumable electrode, no flux or shielding gas | Historical |
| Carbon Arc Welding | (181) | CAW | Carbon electrode, historical | Copper, repair (limited) |
| Flux Cored Arc Welding | 136 138 | FCAW FCAW-S | Continuous consumable electrode filled with flux | Industry, construction |
| Gas Metal Arc Welding | 131 135 | GMAW | Continuous consumable electrode and shielding gas | Industry |
| Gas Tungsten Arc Welding | 141 | GTAW | Nonconsumable electrode, slow, high quality welds | Aerospace, Construction (piping), Tool and Die |
| Plasma Arc Welding | 15 | PAW | Nonconsumable electrode, constricted arc | Tubing, instrumentation |
| Shielded Metal Arc Welding | 111 | SMAW | Consumable electrode covered in flux, can weld any metal as long as they have the right electrode | Construction, outdoors, maintenance |
| Submerged Arc Welding | 121 | SAW | Automatic, arc submerged in granular flux | |
| Magnetically Impelled Arc Butt Welding | 185 | MIAB | Both tube ends are electrodes; no protection gas; arc rotates fast along edge by applied magnetic field | Pipelines and tubes |
| Atomic Hydrogen Welding | (149) | AHW | Two metal electrodes in hydrogen atmosphere | Historical |

## Oxyfuel gas welding

Overview article: Oxy-fuel welding and cutting
| Name | N | AWS | Characteristics | Applications |
| Air acetylene welding | (321) | AAW | Chemical welding process, not popular | Limited |
| Oxyacetylene welding | 311 | OAW | Combustion of acetylene with oxygen produces high-temperature flame, inexpensive equipment | Maintenance, repair |
| Oxygen/Propane welding | 312 | | Gas welding with oxygen/propane flame | |
| Oxyhydrogen welding | 313 | OHW | Combustion of hydrogen with oxygen produces flame | Limited |
| Pressure gas welding | | PGW | Gas flames heat surfaces and pressure produces the weld | Pipe, railroad rails (limited) |

## Resistance welding

Overview article: electric resistance welding
| Name | N | AWS | Characteristics | Applications |
| Resistance spot welding | 21 | RSW | Two pointed electrodes apply pressure and current to two or more thin workpieces | Automobile industry, Aerospace industry |
| Resistance seam welding | 22 | RSEW | Two wheel-shaped electrodes roll along workpieces, applying pressure and current | Aerospace industry, steel drums, tubing |
| Projection welding | 23 | PW | Semi-Automatic, Automatic, Welds are localized at predetermined points. | |
| Flash welding | 24 | FW | | |
| Upset welding | 25 | UW | Butt joint surfaces heated and brought together by force | |

## Solid-state welding

| Name | N | AWS | Characteristics | Applications |
| Coextrusion Welding | | CEW | Dissimilar metals are extruded through the same die | Joining of corrosion resistant alloys to cheaper alloys or alloys with more favorable mechanical properties |
| Cold pressure welding | 48 | CW | Joining of soft alloys such as copper and aluminium below their melting point | Electrical contacts |
| Diffusion welding | 45 | DFW | No weld line visible | Titanium pump impellor wheels |
| Explosion welding | 441 | EXW | Joining of dissimilar materials, e.g. corrosion resistant alloys to structural steels | Transition joints for chemical industry and shipbuilding. Bimetal pipelines |
| Electromagnetic pulse welding | | | Tubes or sheets are accelerated by electromagnetic forces. Oxides are expelled during impact | Automotive industry, pressure vessels, dissimilar material joints |
| Forge welding | (43) | FOW | The oldest welding process in the world. Oxides must be removed by flux or flames. | Damascus steel |
| Friction welding | 42 | FRW | Thin heat affected zone, oxides disrupted by friction, needs sufficient pressure | Aerospace industry, railway, land transport |
| Friction stir welding | 43 | FSW | A rotating non-consumable tool is traversed along the joint line | Shipbuilding, aerospace, railway rolling stock, automotive industry |
| Friction stir spot welding | | FSSW | A rotating non-consumable tool is plunged into overlapping sheets | Automotive industry |
| Hot pressure welding | | HPW | Metals are pressed together at elevated temperatures below the melting point in vacuum or an inert gas atmosphere | Aerospace components |
| Hot isostatic pressure welding | 47 | HPW | A hot inert gas applies the pressure inside a pressure vessel, i.e. an autoclave | Aerospace components |
| Roll welding | | ROW | Bimetallic materials are joined by forcing them between two rotating wheels | Dissimilar materials |
| Ultrasonic welding | 41 | USW | High-frequency vibratory energy is applied to foils, thin metal sheets or plastics. | Solar industries-. Electronics. Rear lights of cars. Diapers. |

## Other types of welding

| Name | N | AWS | Characteristics | Applications |
| Electron beam welding | 51 511 | EBW | Deep penetration, fast, high equipment cost | |
| Electroslag welding | 72 | ESW | Welds thick workpieces quickly, vertical position, steel only, continuous consumable electrode | Heavy plate fabrication, construction, shipbuilding |
| Flow welding (previously cast welding) | | | Distortion is minimized, and the thermal cycle is relatively benign. | Joining rails in situ by liquid metal |
| Induction welding | 74 | IW | | |
| Laser beam welding | 521 522 | LBW | Deep penetration, fast, high equipment cost | Automotive industry |
| Laser-hybrid welding | | | Combines LBW with GMAW in the same welding head, able to bridge gaps up to 2mm (between plates), previously not possible with LBW alone. | Automotive, Shipbuilding, Steelwork industries |
| Percussion welding | 77 | PEW | Following an electrical discharge, pressure is applied which forges the materials together | Components of switch gear devices |
| Thermite welding | 71 | TW | Exothermic reaction between aluminium powder and iron oxide powder | Railway tracks |
| Electrogas welding | 73 | | Continuous consumable electrode, vertical positioning, steel only | Storage tanks, shipbuilding |
| Stud arc welding | 78 | | Welds studs to base material with heat and pressure | |