The Basics of TIG and MIG Welding

TIG and MIG welding custom sheet metal fabrication prototypesTIG and MIG welding are two of the most common arc welding processes. But what exactly do these abbreviations mean?

To better understand the two terms, let’s start by defining what arc welding is.

Arc welding is one of the several fusion methods for joining metals. Usually, two metals are brought together and intense heat applied at the point where they join causing metal at this joint to melt and intermix either directly or with an intermediate filler metal. As the joint cools, it solidifies creating a metallurgical bond. These bonds, having been created by mixing the two metals, will potentially have the same strength properties of the parent metals. Arc welding is therefore different from non-fusion processes such as soldering and brazing in which the physical and mechanical properties of bonds formed at joints don’t duplicate the properties of the parent metals.

Tungsten Inert Gas (TIG) welding

Tungsten Inert Gas welding also commonly known as Gas Tungsten Arc Welding (GTAW) uses a non-consumable tungsten or alloy of tungsten as the electrode. A filler metal may or may not be used.

Tungsten is used because among pure metals it has the highest melting point (3,422°C). The name TIG actually comes from the tungsten electrode and the inert gas (usually argon or helium) surrounding this tungsten. TIG welding is predominantly used in magnesium, stainless steel, copper, and titanium and can also be used for two dissimilar metals. It is also handy for tricky welds such as S-Curves or when welding around things.

When performed by skilled operators, TIG welding can produce some of the highest quality welds. This is partly because of the greater control afforded to the operator. All material used in the process must also be very clean and free of oil, moisture, and dirt. The level of heat applied must be high enough for greater penetration and thus stronger welds. Continue Reading The Basics of TIG and MIG Welding