Many old Mig / Mag welding machines, as well as not being homologated CE, have a torch attack other than the "euro" one.
Here is an example of Euro connector:
In the past, manufacturers of welding machines, but above all torch producers, bound the customer more to buy their spare parts.
After the introduction of the EC directive that regulates the parameters within which a machine can be considered safe for the operator and puts the buyer in conditions to carry out the correct comparisons, the producers of welding machines and torches began to adapt to the so-called "Euro attack".
The euro attack has very specific characteristics that must be the same for all types of MIG / MAG wire welders. Except those of lower amperages that, for reasons of space, do not allow the application of this attack.
From the beginning of the 90s most of the welders are equipped with that attack, so although changing the torch's features and related spare parts (Read here how to find the right spare parts for your MIG / MAG TORCH), have been used to allow the customer to replace the torch without having to make adaptations with all the consequent implications (rendering of the machine, operator safety, etc.).
With this premise we are not saying that it is not possible but we recommend those who want to do it to be aware that this change could involve not always predictable issues. For this reason we recommend being assisted by an electrical engineer possibly with the repair of welding machines.
Euro attacks can be 3 types: 
The Euro Axial and Euro Radial connectors differ for the type of gas pipe connection,
The mini euro for the dimensions of overall dimensions.
All have the same torch attack. (Images taken from the Trafimet catalog).
Alternatively, an adapter can be applied to the torch. In this case it becomes simpler on a part because it is not necessary to make any changes to the machine, but more complicated on the other since it is Indispensable to identify exactly the type of connector.
Some examples always taken from the Trafimet catalog:
In the images it is possible to see how from euro attack on the one hand you pass to the different connectors on the other. The connectors you see are the most disparate, and these are the TWECO, CEA, new, SINCO, CEM, ESAB, Hitachi and Miller.
Each of these has very precise measures that must match that it is necessary to check carefully before placing the order.
These articles are treated only on order and on precise indication of the model we can propose our best offer and indicate delivery times.
If you need an adapter to convert your connector to one with an Euro attack write or call us, the contacts are these:
Whatsapp 348 6018421
Email: info@tecnista.it
Telephone: 0431 621270