Welding processes and ISO 4063 numbers
MMA, MIG/MAG, TIG and the rest — how each one works, what it is for, where it stops being the right choice.
Three processes cover almost all manual welding, and the numbers in EN ISO 4063 are what you will see on a WPS: 111 for stick, 131 and 135 for MIG and MAG, 141 for TIG.
The honest way to choose between them is by what limits you. Outdoors and on dirty or rusty steel, MMA wins because it carries its own shielding in the coating. Where there is a lot of metal to deposit and a roof over your head, MIG/MAG wins on deposition rate and arc-on time. Where the joint is thin, visible or has to be right the first time, TIG wins because it is the only process that separates the heat from the filler.
Each article covers the same ground: how the arc actually behaves, what the settings do, where the process fails and the mistakes that show up in every weld test.
- MMA — stick welding What MMA welding is (manual metal arc, stick, process 111) and how to do it: arc length about one electrode diameter, angle, weave, current by electrode size, bead faults.
- MIG/MAG welding MIG 131 or MAG 135: same machine, different gas. Short-circuit at 16–22 V, spray from 26–28 V, pulsed; wire, voltage and gas by plate thickness, torch angle, faults.
- Flux-cored welding 136 Process 136 = flux-cored wire with shielding gas, 138 = metal-cored, 114 = self-shielded, no gas. Polarity, 15–25 mm stickout, drag angle, E71T-1 and T 46 4 P M21.
- 135 vs 136 vs 138 135 is solid wire, 136 flux-cored, 138 metal-cored — all MAG. Side by side: gas (M21, C1), stick-out 10–15 vs 15–25 mm, slag, positions, fume, what ISO 9606-1 covers.
- Submerged arc welding 121 What 121 means in ISO 4063: solid wire under flux, sub-numbers 122 and 125, positions PA and PB, fused and agglomerated fluxes, operator qualification to ISO 14732.
- Gas welding 311 Tip size by thickness and gas use (2 mm sheet: 155 l/h of acetylene), pressures 2.5 and 0.2–0.5 bar, the neutral flame, filler d = s/2 + 1, flashback.
- TIG welding Process 141 is TIG (GTAW) with filler, 142 without. Amps by thickness (3 mm — 90–130 A), argon 5–12 l/min, AC for aluminium, DC− for steel, tungsten choice.
Frequently asked questions
Which process should a beginner learn first?
MMA, for two reasons. The equipment is one box and two leads, so there is less to go wrong; and because everything is visible and slow, you learn to read the pool. A welder who can run a decent stick bead picks up MIG in an afternoon. The reverse is not true.
What do the numbers 111, 135 and 141 mean?
They are the process numbers of EN ISO 4063, and they are what appears on a WPS and on your certificate rather than the trade names. 111 is manual metal arc, 131 MIG, 135 MAG with solid wire, 136 flux-cored, 141 TIG.
Can I weld outdoors with MIG?
Only behind a screen. About 2 m/s of wind strips the gas shield, and that is a light draught. Outdoors the practical choices are MMA or self-shielded flux-cored wire, both of which carry their protection in the consumable.