MIG, MAG, TIG and MMA welding: differences, certificate

MIG, MAG, TIG and MMA welding differ above all in what protects the liquid weld pool from air: inert gas, active gas, argon or the coating of the electrode. A certificate under the EN ISO 9606 standard is issued for a specific process, material and position, so a MAG welder is not automatically a TIG welder.

How MIG, MAG, TIG and MMA welding differ

Each process has a number under the EN ISO 4063 standard. The same number appears on the welder's certificate and in the job description.

Process	Number	What shields the weld	Wind and drafts	Thin sheet	Speed
MMA (coated electrode)	111	electrode coating that forms slag	least sensitive	poor on thin stainless steel	medium
MIG (solid wire)	131	inert gas	sensitive	good	fast
MAG (solid wire)	135	active gas	sensitive	good	fast
MAG (cored wire)	136	active gas	sensitive	good	fast
TIG (tungsten electrode)	141	argon	most sensitive	good, highest quality	slowest

The most common mistake in course descriptions is swapping MIG and MAG. MIG works in inert gas, MAG in active gas, and the machine and wire can look alike. The second mistake is confusing 135 with 136: both are MAG, but 135 means solid wire and 136 means cored wire.

MIG vs MAG: one torch, a different gas

In MIG and MAG the wire is fed automatically through the torch, and the welder guides the arc by hand. The shielding gas decides the name. Inert gas means MIG (131), active gas means MAG (135 or 136). Both processes are fast and handle thin sheet well, which is why they are common in serial steel structures and on the lines described in the text on work in the automotive industry.

Shielding gas is easy to blow away. A draft from an open hall door can ruin a MIG or MAG weld even when the welder does everything right.

TIG: the highest quality, the most coordination

In TIG (141) the arc burns between a non-consumable tungsten electrode and the material, and the filler is fed separately with the other hand. The pool is shielded by argon. TIG gives the highest weld quality and suits stainless steel and thin sheet, but it is the slowest and demands the most coordination of both hands. It is also the most sensitive to wind.

MMA: coated electrode, resistant to wind

In MMA (111) the welder melts a coated electrode. The coating burns and forms slag that covers the weld, so the process needs no gas cylinder. That is why MMA copes best with wind and work outside the hall. It does worse on thin stainless steel, where TIG is the better choice.

Which EN ISO 9606 certificate for which process

In Poland the welder qualification test for steel is based on the PN-EN ISO 9606-1:2017-10 standard. The next parts of the series (9606-2 to 9606-5) cover aluminium, copper, nickel, titanium and zirconium. The 2012 edition was withdrawn and replaced by the 2017 one.

A certificate does not cover "welding in general". Its scope is set by essential variables:

the welding process, that is number 111, 131, 135, 136 or 141,
the product type: plate or pipe,
the filler material group,
the dimension: plate thickness or pipe diameter,
the welding position,
joint details, for example with a backing or with forming gas.

A welder certified for 135 in one position on plate is not qualified to weld pipe with process 141. Each further process is a separate test at a certifying body, for example TDT or UDT. To be certified at TDT you must be at least 18, have no health contraindications to welding work, know the safety rules and speak Polish well enough to pass the test, if the test requires it.

How long a welder's certificate is valid

The validity period depends on the body and the chosen method of extension. At TDT a certificate can be issued for 3 or for 10 years. Every 6 months the employer named on the certificate confirms that the welder worked within the scope of their qualifications. A missing confirmation, or a break in welding longer than 6 months, ends the validity of the certification.

For steel, TDT provides three ways of periodic verification, and the applicant chooses one:

a repeat practical test every 3 years,
every 2 years, the test results of two production welds made in the last 6 months of validity and examined in a laboratory recognised by TDT,
every 6 months, evidence of work for the same employer, who has an approved quality system under PN-EN ISO 3834-2 or 3834-3.

For pressure equipment some of these methods are not allowed. Certificates for aluminium, copper and nickel are verified every 2 years. Work with several processes therefore means several certificates, each with its own deadline.

A welder's certificate obtained abroad

The procedures for recognising a foreign welder's certificate, for example a Ukrainian one, are not described directly in the regulations. Whether the body will accept earlier qualifications, in what language it will hold the test and whether it will allow an interpreter must be agreed with the examining body. Recognition of school diplomas and certificates is a separate matter, described in the text on nostrification and recognition of qualifications.

Frequently asked questions

Which process is easiest to start learning welding with?

MMA and MAG need less coordination than TIG, because one hand guides the electrode or the wire torch. TIG needs both hands working at once and gives the slowest pace, so it is usually learned later.

Can a MAG welder weld with TIG?

Not without a separate certificate. The welding process is an essential variable, so a qualification for 135 does not cover process 141.

Which process is used outdoors, in wind?

MMA works best, because the weld is protected by slag from the coating, not by gas. MIG, MAG and TIG are sensitive to drafts, and TIG the most.

This text describes the general rules. What you are entitled to depends on your type of contract: an employment contract (umowa o pracę) or a contract of mandate (umowa zlecenie). Your own contract and payslip are what count.