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Mig Welding - Introduction

M.I.G. (Metallic Inert Gas)
This term is only strictly correct when the process being used with an inert gas for sheilding purposes. E.g. Aluminium welding with a pure argon gas sheild

M.A.G.S. (Metallic Arc Gas Sheilding)
This process uses active gas sheilding, for example when welding low cardbon steel in conjunction with argon & Co2 gas cheild.

Mig Nozzle


M.I.G. and M.A.G.S. Working Principle

A continuous consumable wire is fed through a suitable torch or gun which is used both as an electrode and a filler, the gun or torch embodies a concentric gas nozzle which channels a protective gas which is usualy fed from a separate cylinder out and around the newly formed weld preventing atmospheric contamination. The weld is formed due to the positive electrode (the continuous wire) coming into close contact with the negative electrode of the work piece allowing a large current to flow through the wire causing the tip to heat up beyond its melting point.

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