Process numbers: what do 111, 135 and 141 mean?
The welding process numbers according to ISO 4063 — and how to read them
Introduction
On a drawing, in a welding procedure (WPS) and on your welding certificate, the welding process is not given as a name but as a number. 135 means MAG welding with solid wire, whether the paper is written in Denmark, Germany or Poland. The numbers come from the standard ISO 4063.
The current edition is the 5th edition from 2023. It replaces the 2009 edition. The big news in 2023 was that the processes for welding plastics were added to the list.
How the number is built up
The first digit is the main group. Two digits are a group, and three digits are a subgroup. A process number has at most three digits. Example: 1 is arc welding, 13 is gas-shielded arc welding with a consumable wire (MIG and MAG), and 135 is MAG with solid wire.
| Main group | What it covers |
|---|---|
| 1 | Arc welding |
| 2 | Resistance welding, e.g. spot welding |
| 3 | Gas welding |
| 4 | Pressure welding, e.g. friction welding |
| 5 | Beam welding: electron beam and laser |
| 6 | Welding of plastics |
| 7 | Other welding processes, e.g. arc stud welding (78) |
| 8 | Cutting and gouging |
The numbers you will meet in the workshop
The table shows the numbers with the standard's English name in quotation marks, so you can recognise them in a foreign WPS.
| No. | Process (the name in ISO 4063) |
|---|---|
| 111 | Manual metal arc welding with covered electrode («Manual metal arc welding») |
| 114 | Arc welding with self-shielded cored wire, without shielding gas («Self-shielded tubular cored arc welding») |
| 121 | Submerged arc welding with solid wire («Submerged arc welding with solid wire electrode») |
| 131 | MIG welding with solid wire («MIG welding with solid wire electrode») |
| 135 | MAG welding with solid wire («MAG welding with solid wire electrode») |
| 136 | MAG welding with flux-cored wire («MAG welding with flux cored electrode») |
| 138 | MAG welding with metal-cored wire («MAG welding with metal cored electrode») |
| 141 | TIG welding with solid filler wire («TIG welding with solid filler material») |
| 142 | TIG welding without filler material («Autogenous TIG welding») |
| 143 | TIG welding with tubular cored filler wire («TIG welding with tubular cored filler material») |
| 147 | TIG welding with active shielding gas, called TAG («TAG welding») |
| 15 | Plasma welding («Plasma arc welding») |
| 21 | Spot welding, a type of resistance welding («Resistance spot welding») |
| 311 | Gas welding with oxygen and acetylene («Oxyacetylene welding») |
| 52 | Laser welding («Laser welding») |
| 78 | Arc stud welding («Arc stud welding») |
Letters after the number
The working draft of the new ISO 9606 (June 2024) adds more after the number: how the metal transfers from the wire into the weld pool. D means short-circuit transfer, G means globular (large droplets), and S means spray (fine droplets). This applies only to 131, 135 and 138. WF means that the power source's waveform is controlled. Examples from the draft: 131-D and 135-S-WF.
Which numbers do you need to know?
The blacksmith training regulations (in force from 1 August 2026) mention 111, 131, 135, 136, 138, 141 and 142 «according to EN ISO 4063». The draft of the new ISO 9606 also covers, among others, 147 (TAG) and 52 (laser).